c primer plus 10 编程练习

1、

#include <stdio.h>
#define MONTHS 12
#define YEARS 5

int main(void)
{
    const float rain[YEARS][MONTHS] = 
    {
        {4.3, 4.3, 4.3, 3.0, 2.0, 1.2, 0.2, 0.2, 0.4, 2.4, 3.5, 6.6},
        {8.5, 8.2, 1.2, 1.6, 2.4, 0.0, 5.2, 0.9, 0.3, 0.9, 1.4, 7.3},
        {9.1, 8.5, 6.7, 4.3, 2.1, 0.8, 0.2, 0.2, 1.1, 2.3, 6.1, 8.4},
        {7.2, 9.9, 8.4, 3.3, 1.2, 0.8, 0.4, 0.0, 0.6, 1.7, 4.3, 6.2},
        {7.6, 5.6, 3.8, 2.8, 3.8, 0.2, 0.0, 0.0, 0.0, 1.3, 2.6, 5.2}
    };
    int year, month;
    const float (* ptr)[MONTHS];
    ptr = rain;
    
    float subtot, total;
    printf(" YEAR  RAINFALL (inches)
");
    for(year = 0, total = 0; year < YEARS; year++)
    {
        for(month = 0, subtot = 0; month < MONTHS; month++)
        {
            subtot += *(*(ptr + year) + month);
        }    
        printf("%5d  %15.1f
", 2010 + year, subtot);
        total += subtot; 
    }
    printf("
The yearly average is %.1f inches.

", total / YEARS);
    
    printf("MONTHLY AVERAGE:

");
    printf("  Jan  Feb  Mar  Apr  May  Jun  Jul  Aug  Sep  Oct  Nov Dec
");

    
    for(month = 0; month < MONTHS; month++)
    {
        for(year = 0, subtot = 0; year < YEARS; year++)
        {
            subtot += *(*(ptr + year) + month);
        }
        printf("%4.1f ", subtot / YEARS);    
    } 
    printf("
");
    
    return 0;
}

2、

#include <stdio.h>

#define SIZE 5

void copy_arr(double son1[], double mother[], int n);
void copy_ptr(double son2[], double mother[], int n);
void copy_ptrs(double son3[], double mother[], double * ptr);

int main(void)
{
    double data[SIZE] = {1.1, 2.2, 3.3, 4.4, 5.5};
    double target1[SIZE];
    double target2[SIZE];
    double target3[SIZE];
    
    double * ptr = data; 
    copy_arr(target1, data, SIZE);
    copy_ptr(target2, data, SIZE);
    copy_ptrs(target3, data, ptr + SIZE);
    
    int i;
    for(i = 0; i < SIZE; i++)
    {
        printf("target1_%d: %.1f
", i, target1[i]);
        printf("target2_%d: %.1f
", i, target2[i]);
        printf("target3_%d: %.1f
", i, target1[i]);
    }
    
    return 0;
}

void copy_arr(double son1[], double mother[], int n)
{
    int i;
    for(i = 0; i < n; i++)
    {
        son1[i] = mother[i];
    }
}

void copy_ptr(double son2[], double mother[], int n)
{
    int i;
    for(i = 0; i < n; i++)
    {
        *(son2 + i) = *(mother + i);
    }
}

void copy_ptrs(double son3[], double mother[], double * ptr)
{
    double * ptrtem = mother;
    
    while(ptrtem < ptr)
    {
        *son3++ = *ptrtem++;
    }    
}

#include <stdio.h>

void copy_arr(double t[], double s[], int n);
void copy_ptr(double *t, double *s, int n);
void copy_ptrs(double *t, double *s_first, double *s_last);

int main(void)
{
    double source[5] = {1.1, 2.2, 3.3, 4.4, 5.5};
    double target1[5];
    double target2[5];
    double target3[5];
    
    copy_arr(target1, source, 5);
    copy_ptr(target2, source, 5);
    copy_ptrs(target3, source, source + 5);
    
    int i;
    for(i = 0; i < 5; i++)
    {
        printf("target1: %d : %.1f.
", i, target1[i]);
        printf("target2: %d : %.1f.
", i, target2[i]);
        printf("target3: %d : %.1f.
", i, target3[i]);
    }
    
    return 5;    
} 

void copy_arr(double t[], double s[], int n)
{
    int i;
    for(i = 0; i < n; i++)
    {
        t[i] = s[i];
    }
}

void copy_ptr(double *t, double *s, int n)
{
    int i;
    for(i = 0; i < n; i++)
    {
        *(t + i) = *(s + i);
    }
}

void copy_ptrs(double *t, double *s_first, double *s_last)
{
    int i;
    for(i = 0; (s_last - s_first) > i; i++)
    {
        *(t + i) = *(s_first + i);
    }
}

3、

#include <stdio.h>

#define SIZE 6

int get_max(int ar[], int n);

int main(void)
{
    int data[SIZE] = {3, 8, 19, -3, 13, 7};
    
    printf("the max is: %d.
", get_max(data, SIZE));
    
    return 0;
}

int get_max(int ar[], int n)
{
    int i;

    int max = ar[0];
    
    for(i = 1; i < n; i++)
    {
        if(ar[i] > max)
        {
            max = ar[i];
        }
    }
    return max;
}

#include <stdio.h>

#define SIZE 7

int max_get(int * ptr, int n);

int main(void)
{
    int data[SIZE] = {3, 87, 7, 8, 3, 900, 22};
    
    printf("the max is: %d.
", max_get(data, SIZE));
    
    return 0;
}

int max_get(int * ptr, int n)
{
    int i;
    int max = *ptr;
    
    for(i = 1; i < n; i++)
    {
        if(max < *(ptr + i))
        {
            max = *(ptr + i);
        }
    }
    return max;
}

#include <stdio.h>

int get_max(int number[], int n);

int main(void)
{
    int source[100] = {1, 8, 2, 9, 30, 4};
    
    printf("the max: %d.
", get_max(source, 100));
    
    return 0;
}

int get_max(int number[], int n)
{
    int i;
    int max = number[0];
    
    for(i = 0; i < n; i++)
    {
        if(max < number[i])
        {
            max = number[i];
        }
    }
    return max;
}

4、

#include <stdio.h>

#define SIZE 6

int get_index(double ar[], int n);

int main(void)
{
    double data[SIZE] = {2.8, 1.7, 8.7, 19.1, 9.3, 6.5 };
    
    printf("the index of max element: %d.
", get_index(data, SIZE));
    
    return 0;
}

int get_index(double ar[], int n)
{
    int i;
    int index;
    
    double max = ar[0];
    
    for(i = 0; i < n; i++)
    {
        if(max <= ar[i])
        {
            max = ar[i];
            index = i;
        }
    }
    
    return index;
}

#include <stdio.h>

#define SIZE 6

int max_index(double * ptr, int n);

int main(void)
{
    double data[SIZE] = {3.8, 11.2, 8.2, 2.3, 7.6, 4.5};
        
    printf("the max_index: %d.
", max_index(data, SIZE));
    
    return 0;
}

int max_index(double * ptr, int n)
{
    int i, index;
    double max = *ptr;
    
    for(i = 0; i < n; i++)
    {
        if(max <= *(ptr + i))
        {
            max = *(ptr + i);
            index = i;    
        }    
    } 
    return index;
}

#include <stdio.h>

int get_max_index(double number[], int n);

int main(void)
{
    double source[100] = {2.5, 3.2, 1.2, 31.6, 2.4, 0.0, 7.3};
    printf("the max_index: %d.
", get_max_index(source, 100));
    
    return 0;
}

int get_max_index(double number[], int n)
{
    double max = number[0];
    int index = 0;
    int i;
    
    for(i = 0; i < n; i++)
    {
        if(max < number[i])
        {
            max = number[i];
            index = i;
        }
    }
    return index;
}

5、

#include <stdio.h>

#define SIZE 6

double diff(double arg[], int n);

int main(void)
{
    double data[SIZE] = {2.8, 0.2, 3.2, 1.2, 8.8, 2.2};
    
    printf("diff: %.1f.
", diff(data, SIZE));
    
    return 0;
}

double diff(double arg[], int n)
{
    int i;
    double min = arg[0];
    double max = arg[0];
    
    for(i = 0; i < n; i++)
    {
        if(min > arg[i])
        {
            min = arg[i];
        }
        if(max < arg[i])
        {
            max = arg[i];
        }
    }
    return max - min;
}

#include <stdio.h>

#define SIZE 6

double get_diff(double * ptr, int n);

int main(void)
{
    double data[SIZE] = {2.1, 3.3, 1.0, 7.8, 3.2, 4.4};
    
    printf("the diff: %.1f.
", get_diff(data, SIZE));
    
    return 0;
}

double get_diff(double * ptr, int n)
{
    int i;
    double min = *ptr;
    double max = *ptr;
    
    for(i = 0; i < n; i++)
    {
        if(min > *(ptr + i))
        {
            min = *(ptr + i);
        }
        
        if(max < *(ptr + i))
        {
            max = *(ptr + i);
        }
    }
    
    return max - min;
}

#include <stdio.h>

double get_range(double number[], int n);

int main(void)
{
    double source[6] = {2.5, 0.9, 0.3, 0.9, 1.4, 7.9};
    
    printf("the diff: %.1f.
", get_range(source, 6));
    
    return 0;
}

double get_range(double number[], int n)
{
    double max = number[0];
    double min = number[0];
    int i;
    
    for(i = 0; i < n; i++)
    {
        if(max < number[i])
        {
            max = number[i];
        }
        if(min > number[i])
        {
            min = number[i];
        }
    }
    return max - min;
}

6、

#include <stdio.h>

#define SIZE 5

void reverse(double arg[], int n);

int main(void)
{
    double data[SIZE] = {3.8, 1.8, 8.7, 9.2, 7.7};
    
    reverse(data, SIZE);
    
    return 0;
}

void reverse(double arg[], int n)
{
    int i;
    
    for(i = 0; i < n; i++)
    {
        printf("%.1f ", arg[SIZE - 1 - i]);
    }
    putchar('
');
}

#include <stdio.h>

#define SIZE 5

void invert(double * ptr, int n);

int main(void)
{
    double data[SIZE] = {3.3, 4.4, 7.7, 9.9, 5.5};
    
    invert(data, SIZE);
    
    return 0;    
} 

void invert(double * ptr, int n)
{
    int i;
    
    for(i = 0; i < n; i++)
    {
        printf("%.1f  ", *(ptr + n - 1 - i));
    }
}

#include <stdio.h>

#define SIZE 5

void inverse(double arg[], int n);

int main(void)
{
    double data[SIZE] = {88, 77, 33, 99, 44};
    
    inverse(data, SIZE);
    
    return 0;
}

void inverse(double arg[], int n)
{
    int i;
    double temp;
    
    for(i = 0; i < n/2; i++)
    {
        temp = arg[i];
        arg[i] = arg[n - 1 - i];
        arg[n - 1 - i] = temp;
    }
    
    for(i = 0; i < n; i++)
    {
        printf("%.1f  ", arg[i]);
    }
}

#include <stdio.h>

#define SIZE 6

void reverse(double * ptr, int n);

int main(void)
{
    double data[SIZE] = {22, 11, 77, 44, 88, 99};
    
    reverse(data, SIZE);
    
    return 0;
}

void reverse(double * ptr, int n)
{
    int i;
    double temp;
    
    for(i = 0; i < n/2; i++)
    {
        temp = *(ptr + i);
        *(ptr + i) = *(ptr + n - 1 - i);
        *(ptr + n - 1 - i) = temp;
    }
    
    for(i = 0; i < n; i++)
    {
        printf("%.1f  ", *(ptr + i));
    }
}

#include <stdio.h>

void r_sort(double number[], int n);

int main(void)
{
    double source[12] = {2.5, 3.2, 1.2, 1.6, 2.4, 0.1, 5.2, 0.9, 0.3, 0.9, 1.4, 7.3};    
    
    int i;
    for(i = 0; i < 12; i++)
    {
        printf("%g ", source[i]);
    }
    putchar('
');
    
    r_sort(source, 12);
    for(i = 0; i < 12; i++)
    {
        printf("%g ", source[i]);
    }
    putchar('
');
    
    return 0;
}

void r_sort(double number[], int n)
{
    int i, j; double temp;
    
    for(i = 0; i < n; i++)
    {
        for(j = 0; j < n; j++)
        {
            if(number[j] < number[j + 1])
            {
                temp = number[j];
                number[j] = number[j + 1];
                number[j + 1] = temp;
            }
        }
    }
}

#include <stdio.h>

#define SIZE 6

void sort(double * ptr, int n);

int main(void)
{
    double data[SIZE] = {3, 7, 2, 48, 99, 6};
    int i;
    
    sort(data, SIZE);
    
    for(i = 0; i < SIZE; i++)
    {
        printf("%g ", data[i]);
    }
    
    return 0;
}

void sort(double * ptr, int n)
{
    int i, j;
    double temp;
    
    for(i = 0; i < n; i++)
    {
        for(j = 0; j < n; j++)
        {
            if(*(ptr + j) < *(ptr + j + 1))
            {
                temp = *(ptr + j);
                *(ptr + j)  = *(ptr + j + 1);
                *(ptr + j + 1) = temp;
            }
        }
    }
}

#include <stdio.h>

void r_sort(double number[], int n);

int main(void)
{
    double source[12] = {2.5, 3.2, 1.2, 1.6, 2.4, 0.1, 5.2, 0.9, 0.3, 0.9, 1.4, 7.3};
    int i;
    
    for(i = 0; i < 12; i++)
    {
        printf("%g ", source[i]);
    }
    putchar('
');
    
    r_sort(source, 12);
    for(i = 0; i < 12; i++)
    {
        printf("%g ", source[i]);
    }
    return 0;
}

void r_sort(double number[], int n)
{
    double temp;
    int i, j;
    
    for( i = 0; i < n - 1; i++)
    {
        for(j = 0; j < n - 1 - i; j++)
        {
            if(number[j] < number[j + 1])
            {
                temp = number[j];
                number[j] = number[j + 1];
                number[j + 1] = temp;
            }
        }
    }
}

7、

#include <stdio.h>

#define ROWS 4
#define COLS 2

void copy_ptr(double *t, double *s, int n);
void copy_2d_ptr(double (*t)[ROWS], double (*s)[ROWS], int n);

int main(void)
{
    double target[COLS][ROWS];
    double source[COLS][ROWS] = {{4.3, 4.3, 4.3, 3.0},{8.5, 8.2, 1.2, 1.6}};
    copy_2d_ptr(target, source, COLS);
    
    int i, j;
    for( i = 0; i < COLS; i++)
    {
        for(j = 0; j < ROWS; j++)
        {
            printf("%.1f  ", target[i][j]);
        }
        putchar('
');
    }
    return 0;
}

void copy_ptr(double *t, double *s, int n)
{
    int i;
    for(i = 0; i < n; i++)
    {
        *(t + i) = *(s + i);
    }
}

void copy_2d_ptr(double (*t)[ROWS], double (*s)[ROWS], int n)
{
    int i;
    for(i = 0; i < n; i++)
    {
        copy_ptr(*(t + i), *(s + i), ROWS);
    }
}

#include <stdio.h>

#define ROWS 2
#define COLS 4

void copy_array_1d(double s[], double t[], int n);
void copy_array_2d(double s[][COLS], double t[][COLS], int n);

int main(void)
{
    double data[ROWS][COLS] = {{3, 2, 7, 9},{1, 4, 5, 8}};
    double target[ROWS][COLS];
    
    int i;
    copy_array_2d(data, target, ROWS);
    
    printf("show the copy result: 
");
    int j;
    for(i = 0; i < ROWS; i++)
    {
        for(j = 0; j < COLS; j++)
        {
            printf("%.1f  ", target[i][j]);
        }
        putchar('
');
    }
    
    return 0;
}

void copy_array_1d(double s[], double t[], int n)
{
    int i;
    for(i = 0; i < n; i++)
    {
        t[i] = s[i];
    }
}

void copy_array_2d(double s[][COLS], double t[][COLS], int n)
{
    int i;
    for(i = 0; i < n; i++)
    {
        copy_array_1d(s[i], t[i], COLS);
    }
}

#include <stdio.h>

#define ROWS 2
#define COLS 4

void array1_copy(double * s, double * t, int n);
void array2_copy(double (* s)[COLS], double (* t)[COLS], int n);

int main(void)
{
    double data[ROWS][COLS] = {{2, 3, 7, 6},{1, 5, 4, 9}};
    double target[ROWS][COLS];
    
    array2_copy(data, target, ROWS);
    
    int i, j;
    for(i = 0; i < ROWS; i++)
    {
        for(j = 0; j < COLS; j++)
        {
            printf("%.1f  ", target[i][j]);
        }
        putchar('
');
    }
    
    return 0;
}

void array1_copy(double * s, double * t, int n)
{
    int i;
    for(i = 0; i < n; i++)
    {
        *(t + i) = *(s + i);
    }
}

void array2_copy(double (* s)[COLS], double (* t)[COLS], int n)
{
    int i;
    for(i = 0; i < n; i++)
    {
        array1_copy(*(s + i), *(t + i), COLS);
    }
}

8、

#include <stdio.h>

#define SIZE 7

void copy_array(double *s, double *t, int n);

int main(void)
{
    double data[SIZE] = {3, 7, 2, 8, 4, 6, 9};
    double target[3];
    
    double * ptr = data + 2;
    copy_array(ptr, target, 3);
    
    int i;
    for(i = 0; i < 3; i++)
    {
        printf("target[%d]: %.1f.
", i, target[i]);
    }
    
    return 0;
} 

void copy_array(double *s, double *t, int n)
{
    int i;
    for(i = 0; i < n; i++)
    {
        *(t + i) = *(s + i);
    }
}

#include <stdio.h>
#include <stdlib.h>

void copy_ptr(double *t, double *s, int n);

int main(void)
{
    double src[] = {1, 2, 3, 4, 5, 6, 7};
    double targ[3];
    
    copy_ptr(targ, src + 2, 3);
    
    int i;
    for(i = 0; i < 3; i++)
    {
        printf("targ[%d]: %.1f.
", i, targ[i]);
    }
    
    return 0;
}

void copy_ptr(double *t, double *s, int n)
{
    int i;
    for(i = 0; i < n; i++)
    {
        *(t + i) = *(s + i);
    }
}

#include <stdio.h>

#define SIZE 7

void array_copy(double *s, double *t, int n);

int main(void)
{
    double data[SIZE] = {1, 2, 3, 4, 5, 6, 7};
    double target[3];
    
    array_copy(data + 2, target, 3);
    
    int i;
    for(i = 0; i < 3; i++)
    {
        printf("%.1f  ", target[i]);
    }
    printf("
");
    
    return 0;
}

void array_copy(double *s, double *t, int n)
{
    int i;
    for(i = 0; i < n; i++)
    {
        *(t + i) = *(s + i);
    }
}

 9、

#include <stdio.h>

#define ROWS 2
#define COLS 6

void copy_array(int rows, int cols, double s[rows][cols], double t[rows][cols]);
void show_array(int rows, int cols, double s[rows][cols]);

int main(void)
{
    double source[ROWS][COLS] = {{3, 2, 8, 5, 9, 4},{3, 6, 2, 1, 7, 9}};
    double target[ROWS][COLS];
    show_array(ROWS, COLS, source);
    
    puts("===========================
");
    copy_array(ROWS, COLS, source, target);
    show_array(ROWS, COLS, target);
    
    return 0;
}

void copy_array(int rows, int cols, double s[rows][cols], double t[rows][cols])
{
    int i, j;
    for(i = 0; i < rows; i++)
    {
        for(j = 0; j < cols; j++)
        {
            t[i][j] = s[i][j];
        }
    }
}

void show_array(int rows, int cols, double s[rows][cols])
{
    int i, j;
    for(i = 0; i < rows; i++)
    {
        for(j = 0; j < cols; j++)
        {
            printf("%5.1f  ", s[i][j]);
        }
        putchar('
');
    }
}

#include <stdio.h>

#define ROWS 3
#define COLS 5

void copy_array(int n, int m, double target[n][m], double source[n][m]);
void show_array(int n, int m, double array[n][m]);

int main(void)
{
    double target[ROWS][COLS];
    double source[ROWS][COLS] = {
    {0.2, 0.4, 2.4, 3.5, 6.6},
    {8.5, 8.2, 1.2, 1600, 2.4},
    {9.1, 8.5, 2.3, 6.1, 8.4}
    };
    
    copy_array(ROWS, COLS, target, source);
    show_array(ROWS, COLS, target);
    
    return 0;
}

void copy_array(int n, int m, double target[n][m], double source[n][m])
{
    int i, j;
    for(i = 0; i < n; i++)
    {
        for(j = 0; j < m; j++)
        {
            target[i][j] = source[i][j];
        }
    }
}

void show_array(int n, int m,double array[n][m])
{
    int i, j;
    for(i = 0; i < n; i++)
    {
        for(j = 0; j < m; j++)
        {
            printf("%.1f  ", array[i][j]);
        }
        putchar('
');
    }
}

10、

#include <stdio.h>

#define SIZE 4

void plus(int array1[], int array2[], int array[3], int n);

int main(void)
{
    int data1[SIZE] = {2, 4, 5, 8};
    int data2[SIZE] = {1, 0, 4, 6};
    int data3[SIZE] = {0};
    int i;
    
    plus(data1, data2, data3, SIZE);
    
    for(i = 0; i < SIZE; i++)
    {
        printf("%d  ", data3[i]);
    }
    putchar('
');
    
    return 0;
}

void plus(int array1[], int array2[], int array3[], int n)
{
    int i;
    
    for(i = 0; i < n; i++)
    {
        array3[i] = array1[i] + array2[i];
    }
}

#include <stdio.h>

#define SIZE 4

void add(int * ptr1, int * ptr2, int * ptr3, int n);

int main(void)
{
    int array1[SIZE] = {20, 4, 500, 8};
    int array2[SIZE] = {1, 100, 4, 60};
    int array3[SIZE] = {0};
    
    add(array1, array2, array3, SIZE);
    
    int i;
    for(i = 0; i < SIZE; i++)
    {
        printf("%d  ", array3[i]);
    }
    
    return 0;
}

void add(int *ptr1, int *ptr2, int *ptr3, int n)
{
    int i;
    for(i = 0; i < n; i++)
    {
        *(ptr3 + i) = *(ptr1 + i) + *(ptr2 + i);
    }
}

#include <stdio.h>

#define INDEX 4

void add_array(int n, int t[], int s1[], int s2[]);

int main(void)
{
    int sum[INDEX], s1[INDEX] = {2, 4, 5, 8}, s2[INDEX] = {1, 200, 4, 6};
    
    add_array(INDEX, sum, s1, s2);
    
    int i;
    for(i = 0; i < INDEX; i++)
    {
        printf("%d ", sum[i]);
    }
    putchar('
');
    
    return 0;
}

void add_array(int n, int t[], int s1[], int s2[])
{
    int i;
    for(i = 0; i < n; i++)
    {
        t[i] = s1[i] + s2[i];
    }
}

11、

#include <stdio.h>

#define ROWS  2
#define COLS  4

void show(int arg[][COLS], int n);
void dup(int arg[][COLS], int n);

int main(void)
{
    int data[2][4] = {{20, 34, 13, 26},{17, 28, 19, 40}};
    
    show(data, ROWS);
    dup(data, ROWS);
    show(data, ROWS);
    
    return 0;
}

void show(int arg[][COLS], int n)
{
    int r, c;
    for(r = 0; r < n; r++)
    {
        for(c = 0; c < COLS; c++)
        {
            printf("%d  ", arg[r][c]);
        }
    }
    putchar('
');
}

void dup(int arg[][COLS], int n)
{
    int r, c;
    for(r = 0; r < n; r++)
    {
        for(c = 0; c < COLS; c++)
        {
            arg[r][c] *= 2;
        }
    }
}

#include <stdio.h>

#define ROWS 2
#define COLS 4

void exhibit(int (* arg)[4], int n);
void dup2(int (* arg)[4], int n);

int main(void)
{
    int data[ROWS][COLS] = {{22, 34, 23, 11},{30, 13, 43, 26}};
    
    exhibit(data, ROWS);
    dup2(data, ROWS);
    exhibit(data, ROWS);
    
    return 0;
}

void exhibit(int (* arg)[4], int n)
{
    int i, j;
    for(i = 0; i < n; i++)
    {
        for(j = 0; j < COLS; j++)
        {
            printf("%d  ", *(*(arg + i) + j));
        }
    }
    putchar('
');
}

void dup2(int (* arg)[4], int n)
{
    int i, j;
    for(i = 0; i < n; i++)
    {
        for(j = 0; j < COLS; j++)
        {
            *(*(arg + i) + j) *= 2;
        }
    }
}

#include <stdio.h>

#define COLS 5
#define ROWS 3

void show_element(int rows, int cols, int t[rows][cols]);
void double_element(int rows, int cols, int t[rows][cols]);

int main(void)
{
    int arr[ROWS][COLS] = {{1, 0, 4, 6, 9},{2, 5, 6, 8, 3},{5, 3, 21, 1, 6}};
    show_element(ROWS,COLS, arr);
    double_element(ROWS, COLS, arr);
    printf("
");
    show_element(ROWS, COLS, arr);
    
    return 0;
}

void show_element(int rows, int cols, int t[rows][cols])
{
    int i, j;
    for(i = 0; i < rows; i++)
    {
        for(j = 0; j < cols; j++)
        {
            printf("%3d ", t[i][j]);    
        }    
    }    
} 

void double_element(int rows, int cols, int t[rows][cols])
{
    int i, j;
    for(i = 0; i < rows; i++)
    {
        for(j = 0; j < cols; j++)
        {
            t[i][j] *= 2;
        }
    }
    
}

12、

#include <stdio.h>

#define MONTHS 12
#define YEARS 5

void year(double ar[][MONTHS], int rows, int cols);
void sum(double ar[][MONTHS], int rows, int cols);
void mean_month(double ar[][MONTHS], int rows, int cols);

int main(void)
{
    double rain[YEARS][MONTHS] = 
    {
        {4.3, 4.3, 4.3, 3.0, 2.0, 1.2, 0.2, 0.2, 0.4, 2.4, 3.5, 6.6},
        {8.5, 8.2, 1.2, 1.6, 2.4, 0.0, 5.2, 0.9, 0.3, 0.9, 1.4, 7.3},
        {9.1, 8.5, 6.7, 4.3, 2.1, 0.8, 0.2, 0.2, 1.1, 2.3, 6.1, 8.4},
        {7.2, 9.9, 8.4, 3.3, 1.2, 0.8, 0.4, 0.0, 0.6, 1.7, 4.3, 6.2},
        {7.6, 5.6, 3.8, 2.8, 3.8, 0.2, 0.0, 0.0, 0.0, 1.3, 2.6, 5.2}
    };
    
    year(rain, YEARS, MONTHS);
    sum(rain, YEARS, MONTHS);
    mean_month(rain, YEARS, MONTHS);
    
    return 0;
}

void year(double ar[][MONTHS], int rows, int cols)
{
    int i, j;
    double temp;
    for(i = 0; i < rows; i++)
    {
        for(temp = 0, j = 0; j < cols; j++)
        {
            temp += ar[i][j];
        }
        printf("%.1f.
", temp);
    }
    putchar('
');
}

void sum(double ar[][MONTHS], int rows, int cols)
{
    int i, j;
    double sum = 0;
    for(i = 0; i < rows; i++)
    {
        for(j = 0; j < cols; j++)
        {
            sum += ar[i][j];
        }
    }
    printf("AVERAGE_year: %.1f.

", sum/rows);
}

void mean_month(double ar[][MONTHS], int rows, int cols)
{
    int i, j;
    double temp;
    for(i = 0; i < cols; i++)
    {
        for(temp = 0, j = 0; j < rows; j++)
        {
            temp += ar[j][i];
        }
        printf("%.1f  ", temp/rows);
    }
    putchar('
');
}

#include <stdio.h>

#define MONTHS 12
#define YEARS 5
void year_average(int years, int months, float t[years][months]);
void month_average(int years, int months, float t[years][months]);

int main(void)
{
    float rain[YEARS][MONTHS] = 
    {
        {4.3, 4.3, 4.3, 3.0, 2.0, 1.2, 0.2, 0.2, 0.4, 2.4, 3.5, 6.6},
        {8.5, 8.2, 1.2, 1.6, 2.4, 0.0, 5.2, 0.9, 0.3, 0.9, 1.4, 7.3},
        {9.1, 8.5, 6.7, 4.3, 2.1, 0.8, 0.2, 0.2, 1.1, 2.3, 6.1, 8.4},
        {7.2, 9.9, 8.4, 3.3, 1.2, 0.8, 0.4, 0.0, 0.6, 1.7, 4.3, 6.2},
        {7.6, 5.6, 3.8, 2.8, 3.8, 0.2, 0.0, 0.0, 0.0, 1.3, 2.6, 5.2}
    };
    year_average(YEARS, MONTHS, rain);
    month_average(YEARS, MONTHS, rain);
    
    return 0;
}

void year_average(int years, int months, float t[years][months])
{
    int i, j;
    float subtot, total;
    for(i = 0, total = 0; i < years; i++)
    {
        for(j = 0, subtot = 0; j < months; j++)
        {
            subtot += t[i][j];
        }
        printf("%d: %.1f
", 2010 + i, subtot);
        total += subtot;
    }
    printf("year_average: %.1f.
", total/years);
}

void month_average(int years, int months, float t[years][months])
{
    int i, j;
    float subtot;
    for(i = 0; i < months; i++)
    {
        for(subtot = 0, j = 0; j < years; j++)
        {
            subtot += t[j][i];
        }
        printf("%.1f  ", subtot/years);
    }
}

13、

#include <stdio.h>
#define ROWS 3
#define COLS 5

void get_row_average(double ar[], int n);
double get_all_average(double ar[][COLS], int n);
double get_max(double ar[][COLS], int n);

int main(void)
{
    int i, j;
    double data[ROWS][COLS];
    
    printf("please input 15 double number.
");
    for(i = 0; i < ROWS; i++)
    {
        for(j = 0; j < COLS; j++)
        {
            printf("data[%d][%d] = ", i, j);
            scanf("%lf", &data[i][j]);    
        }    
    } 
    
    for(i = 0; i < ROWS; i++)
    {
        printf("line %d: ", i + 1);
        get_row_average(data[i], COLS);
    }
    
    printf("all_average: %.1f.
", get_all_average(data, ROWS));
    
    printf("the max: %.1f.
", get_max(data, ROWS));
    
    return 0;
}

void get_row_average(double ar[], int n)
{
    int i;
    double temp = 0;
    for(i = 0; i < n; i++)
    {
        temp += ar[i];
    }
    printf("average: %.1f.
", temp/n);
}

double get_all_average(double ar[][COLS], int n)
{
    int i, j;
    double sum = 0;
    for(i = 0; i < n; i++)
    {
        for(j = 0; j < COLS; j++)
        {
            sum += ar[i][j];    
        }    
    }    
    return sum/(n * COLS);
}

double get_max(double ar[][COLS], int n)
{
    int i, j;
    double max = ar[0][0];
    
    for(i = 0; i < n; i++)
    {
        for(j = 0; j < COLS; j++)
        {
            if(max < ar[i][j])
            {
                max = ar[i][j];
            }
        }
    }
    return max;
}

#include <stdio.h>

#define ROWS 3
#define COLS 5

void input_array(int rows, double arr[][COLS]);

double col_average(int cols, double arr[]);
double array_average(int rows, double arr[][COLS]);
double array_max_number(int rows, double arr[][COLS]);
void show_result(int rows, double arr[][COLS]);

int main(void)
{
    double array[ROWS][COLS];
    input_array(ROWS, array);
    show_result(ROWS, array);
    printf("
");
    
    
    
    return 0;
}

void input_array(int rows, double arr[][COLS])
{
    printf("Enter the array number.
");
    int i, j;
    for(i = 0; i < rows; i++)
    {
        printf("Enter five double number by enter:
");
        for(j = 0; j < COLS; j++)
        {
            scanf("%lf", &arr[i][j]);
        }
    }
}

double col_average(int cols, double arr[])
{
    double sum = 0;
    int i;
    for(i = 0; i < cols; i++)
    {
        sum += arr[i];
    }
    return sum/cols;
}

double array_average(int rows, double arr[][COLS])
{
    double sum = 0;
    int i;
    for(i = 0; i < rows; i++)
    {
        sum += col_average(COLS, arr[i]);
    }
    return sum/rows;
}

double array_max_number(int rows, double arr[][COLS])
{
    double max = arr[0][0];
    int i, j;
    for(i = 0; i < rows; i++)
    {
        for(j = 0; j < COLS; j++)
        {
            if(max < arr[i][j])
            {
                max = arr[i][j];    
            }    
        }    
    } 
    return max;
}

void show_result(int rows, double arr[][COLS])
{
    printf("Now, let's check the array!
");
    printf("The array you input is:
");
    int i, j;
    for(i = 0; i < rows; i++)
    {
        for(j = 0; j < COLS; j++)
        {
            printf("%5g", arr[i][j]);
        }
    }
    putchar('
');
    
    printf("The avrage of every colum is. 
");
    
    for(i = 0; i < rows; i++)
    {
        printf("The average is %g.
", col_average(COLS, arr[i]));
    }
    
    printf("The array's data average is %g
", array_average(ROWS, arr));
    printf("The max datum in the array is %g
", array_max_number(ROWS, arr));
}

#include <stdio.h>

#define ROWS 3
#define COLS 5

void get_array(int rows, double ar[][COLS]);
double row_mean(int num, double ar[]);
double all_mean(int rows, double ar[][COLS]);
double get_max(int rows, double ar[][COLS]);
void show_outcome(int rows, double ar[][COLS]);

int main(void)
{
    double data[ROWS][COLS];
    get_array(ROWS, data);
    show_outcome(ROWS, data);
    
    return 0;
}

void get_array(int rows, double ar[][COLS])
{
    int i, j;
    for(i = 0; i < rows; i++)
    {
        printf("input five double num(then enter): ");
        for(j = 0; j < COLS; j++)
        {
            scanf("%lf", &ar[i][j]);
        }
    }
}

double row_mean(int num, double ar[])
{
    int i;
    double sum = 0;
    for(i = 0; i < num; i++)
    {
        sum += ar[i];
    }
    return sum/num;
}

double all_mean(int rows, double ar[][COLS])
{
    int i;
    double sum = 0;
    for(i = 0; i < rows; i++)
    {
        sum += row_mean(COLS, ar[i]);
    }
    return sum/rows;
}

double get_max(int rows, double ar[][COLS])
{
    int i, j;
    double max = ar[0][0];
    for(i = 0; i < rows; i++)
    {
        for(j = 0; j < COLS; j++)
        {
            if(max < ar[i][j])
            {
                max = ar[i][j];
            }
        }
    }
    return max;
}

void show_outcome(int rows, double ar[][COLS])
{
    printf("Now let us check the result!
");
    
    int i, j;
    for(i = 0; i < rows; i++)
    {
        for(j = 0; j < COLS; j++)
        {
            printf("%.1f  ", ar[i][j]);
        }
    }
    putchar('
');
    
    for(i = 0; i < rows; i++)
    {
        printf("lines %d average: %.1f.
", i + 1, row_mean(COLS, ar[i]));
        
    }
    
    printf("all mean: %.1f   
", all_mean(rows, ar));
    printf("the  max: %.1f   
", get_max(rows, ar)); 
}

14、

#include <stdio.h>

#define ROWS 3
#define COLS 5

void get_line_average(int num, double ar[num]);

double get_all_average(int rows, int cols, double ar[rows][cols]);

double get_max(int rows, int cols, double ar[rows][cols]);

int main(void)
{
    double data[ROWS][COLS];
    int i, j;
    
    printf("please input 15 double numbers.
");
    for(i = 0; i < ROWS; i++)
    {
        for(j = 0; j < COLS; j++)
        {
            printf("data[%d][%d]: ", i, j);
            scanf("%lf", &data[i][j]);
        }
    }
    
    for(i = 0; i < ROWS; i++)
    {
        get_line_average(COLS, data[i]);
    }
    
    printf("all_average: %.1f.
", get_all_average(ROWS, COLS, data));
    
    printf("the max: %.1f.
", get_max(ROWS, COLS, data));
    
    return 0;
}

void get_line_average(int num, double ar[num])
{
    int i;
    double temp = 0;
    for(i = 0; i < num; i++)
    {
        temp += ar[i];
    }
    printf("average: %.1f.
", temp/num);
}

double get_all_average(int rows, int cols, double ar[rows][cols])
{
    int i, j;
    double sum = 0;
    for(i = 0; i < rows; i++)
    {
        for(j = 0; j < cols; j++)
        {
            sum += ar[i][j];
        }
    }
    return sum/(rows * cols);
}

double get_max(int rows, int cols, double ar[rows][cols])
{
    int i, j;
    double max = ar[0][0];
    
    for(i = 0; i < rows; i++)
    {
        for(j = 0; j < cols; j++)
        {
            if(max < ar[i][j])
            {
                max = ar[i][j];
            }
        }
    }
    return max;
}

#include <stdio.h>

#define ROWS 3
#define COLS 5

void get_array(int rows, int cols, double ar[rows][cols]);

void get_line_average(int num, double ar[num]);

double get_all_average(int rows, int cols, double ar[rows][cols]);

double get_max(int rows, int cols, double ar[rows][cols]);

int main(void)
{
    double data[ROWS][COLS];
    int i, j;
    
    get_array(ROWS, COLS, data);
    
    for(i = 0; i < ROWS; i++)
    {
        get_line_average(COLS, data[i]);
    }
    
    printf("all_average: %.1f.
", get_all_average(ROWS, COLS, data));
    
    printf("the max: %.1f.
", get_max(ROWS, COLS, data));
    
    return 0;
}

void get_array(int rows, int cols, double ar[rows][cols])
{
    int i, j;
    printf("please input 15 double num.
"); 
    for(i = 0; i < rows; i++)
    {
        for(j = 0; j < cols; j++)
        {
            printf("ar[%d][%d]: ", i, j);
            scanf("%lf", &ar[i][j]);
        }
    }
}


void get_line_average(int num, double ar[num])
{
    int i;
    double temp = 0;
    for(i = 0; i < num; i++)
    {
        temp += ar[i];
    }
    printf("average: %.1f.
", temp/num);
}

double get_all_average(int rows, int cols, double ar[rows][cols])
{
    int i, j;
    double sum = 0;
    for(i = 0; i < rows; i++)
    {
        for(j = 0; j < cols; j++)
        {
            sum += ar[i][j];
        }
    }
    return sum/(rows * cols);
}

double get_max(int rows, int cols, double ar[rows][cols])
{
    int i, j;
    double max = ar[0][0];
    
    for(i = 0; i < rows; i++)
    {
        for(j = 0; j < cols; j++)
        {
            if(max < ar[i][j])
            {
                max = ar[i][j];
            }
        }
    }
    return max;
}

#include <stdio.h>

#define ROWS 3
#define COLS 5

void get_array(int rows, int cols, double ar[rows][cols]);

double get_line_mean(int num, double ar[num]);

double get_all_mean(int rows, int cols, double ar[rows][cols]);

double get_all_max(int rows, int cols, double ar[rows][cols]);

void show_result(int rows, int cols, double ar[rows][cols]);

int main(void)
{
    double data[ROWS][COLS];
    
    get_array(ROWS, COLS, data);
    
    show_result(ROWS, COLS, data);
    
    return 0;
}

void get_array(int rows, int cols, double ar[rows][cols])
{
    int i, j;
    printf("please input 15 double number.
");
    for(i = 0; i < rows; i++)
    {
        for(j = 0; j < cols; j++)
        {
            printf("data[%d][%d]: ", i, j);
            scanf("%lf", &ar[i][j]);
        }
    }
}

double get_line_mean(int num, double ar[num])
{
    int i;
    double temp = 0;
    for(i = 0; i < num; i++)
    {
        temp += ar[i];
    }
    return temp/num;
}

double get_all_mean(int rows, int cols, double ar[rows][cols])
{
    int i, j;
    double sum;
    for(i = 0; i < rows; i++)
    {
        sum += get_line_mean(cols, ar[i]);
    }
    return sum/rows;
}

double get_all_max(int rows, int cols, double ar[rows][cols])
{
    int i, j;
    double max = ar[0][0];
    for(i = 0; i < rows; i++)
    {
        for(j = 0; j < cols; j++)
        {
            if(max < ar[i][j])
            {
                max = ar[i][j];
            }
        }
    }
    return max;
}

void show_result(int rows, int cols, double ar[rows][cols])
{
    int i, j;
    printf("Let us check the result!
");
    
    for(i = 0; i < rows; i++)
    {
        for(j = 0; j < cols; j++)
        {
            printf("%.1f  ", ar[i][j]);
        }
        putchar('
');
    }
    putchar('
');
    
    printf("Show the lien mean!
");
    
    for(i = 0; i < rows; i++)
    {
        printf("lines %d mean: %.1f
", i + 1, get_line_mean(cols, ar[i]));
    }
    
    printf("all mean: %.1f.
", get_all_mean(rows, cols, ar));
    
    printf("all max:  %.1f.
", get_all_max(rows, cols, ar));
}

#include <stdio.h>

void input_array(int rows, int cols, double arr[rows][cols]);
double col_average(int cols, double arr[cols]);
double array_average(int rows, int cols, double arr[rows][cols]);
double array_max_number(int rows, int cols, double arr[rows][cols]);
void show_result(int rows, int cols, double arr[rows][cols]);

int main(void)
{
    int rows = 3;
    int cols = 5;
    double array[rows][cols];
    input_array(rows, cols, array);
    show_result(rows, cols, array);
    return 0;    
} 

void input_array(int rows, int cols, double arr[rows][cols])
{
    int i, j;
    printf("Enter the array number.
");
    for(i = 0; i < rows; i++)
    {
        printf("Enter five double number seperate by enter:
");
        for(j = 0; j < cols; j++)
        {
            scanf("%lf", &arr[i][j]);
        }
    }
}

double col_average(int cols, double arr[cols])
{
    double sum = 0;
    int i;
    for(i = 0; i < cols; i++)
    {
        sum += arr[i];
    }
    return sum/cols;
}

double array_average(int rows, int cols, double arr[rows][cols])
{
    double sum = 0;
    int i;
    for(i = 0; i < rows; i++)
    {
        sum += col_average(cols, arr[i]);
    }
    return sum/rows;
}

double array_max_number(int rows, int cols, double arr[rows][cols])
{
    double max = arr[0][0];
    int i, j;
    for(i = 0; i < rows; i++)
    {
        for(j = 0; j < cols; j++)
        {
            if(max < arr[i][j])
            {
                max = arr[i][j];
            }
        }
    }
    return max;
}

void show_result(int rows, int cols, double arr[rows][cols])
{
    printf("Now, let us check the result!
");
    printf("The array you input is!
 ");
    int i, j;
    for(i = 0; i < rows; i++)
    {
        for(j = 0; j < cols; j++)
        {
            printf("%5g", arr[i][j]);
        }
    }
    putchar('
');
    
    printf("The average of every line is!
");
    for(i = 0; i < rows; i++)
    {
        printf("the %d line's average is %g .
", i + 1, col_average(cols, arr[i]));
    }
    
    printf("The array data average is  %g  
", array_average(rows, cols, arr));
    printf("The max datum in the array is %g 
", array_max_number(rows, cols, arr));
}