c语言 9-6

1、

#include <stdio.h>

int search(char x[], int c)
{
    int i = 0, j = 0;
    while(1)
    {
        if(x[i] == c)
        {
            j++;
        }
        if(x[i] == '')
            break;
        i++;
    }
    return j == 0 ? 0 : j;
}

int main(void)
{
    char str[128];
    printf("str:  "); scanf("%s", str);
    printf("c number: %d
", search(str, 'c'));
    return 0; 
}

2、

#include <stdio.h>

int search(char x[], int key)
{
    int i = 0, j = 0;
    while(x[i] != '')
    {
        if(x[i] == key)
            j++;
        i++;
    }
    return j;
}

int main(void)
{
    char str[129];
    printf("str:  "); scanf("%s", str);
    printf("c number:  %d
", search(str,'c'));
    return 0;
}

3、

#include <stdio.h>

int search(char x[], int key)
{
    int i = 0, j = 0;
    while(x[i])
    {
        if(x[i] == key)
            j++;
        i++;
    }
    return j;
}

int main(void)
{
    char str[128];
    printf("str  "); scanf("%s", str);
    printf("c number:  %d
", search(str, 'c'));
    return 0;
}