JZ-C-20

剑指offer第二十题：顺时针打印矩形

//============================================================================
// Name        : JZ-C-20.cpp
// Author      : Laughing_Lz
// Version     :
// Copyright   : All Right Reserved
// Description : 顺时针打印矩形
//============================================================================

#include <iostream>
#include <stdio.h>
using namespace std;

void PrintMatrixInCircle(int** numbers, int columns, int rows, int start);
void printNumber(int number);
void PrintMatrixClockwisely(int ** numbers, int columns, int rows) {
    if (numbers == NULL || columns <= 0 || rows <= 0) {
        return;
    }
    int start = 0;
    //每次循环打印一个圆
    while (start * 2 < columns && start * 2 < rows) { //可循环打印的条件
        PrintMatrixInCircle(numbers, columns, rows, start);
        start++;
    }
}
void PrintMatrixInCircle(int** numbers, int columns, int rows, int start) {
    int endX = columns - 1 - start;
    int endY = rows - 1 - start;
    //从左到右打印
    for (int i = start; i <= endX; i++) {
        printNumber(numbers[start][i]);
    }
    //从上到下打印
    if (start < endY) {
        for (int i = start + 1; i <= endY; i++) {
            printNumber(numbers[i][endX]);
        }
    }
    //从右到左打印
    if (start < endX && start < endY) {
        for (int i = endX - 1; i >= start; i--) {
            printNumber(numbers[endY][i]);
        }
    }
    //从下到上打印
    if (start < endY - 1 && start < endX) {
        for (int i = endY - 1; i >= start + 1; i--) {
            printNumber(numbers[i][start]);
        }
    }
}
void printNumber(int number) {
    printf("%d	", number);
}
// ====================测试代码====================
void Test(int columns, int rows)
{
    printf("Test Begin: %d columns, %d rows.
", columns, rows);

    if(columns < 1 || rows < 1)
        return;

    int** numbers = new int*[rows];
    for(int i = 0; i < rows; ++i)
    {
        numbers[i] = new int[columns];
        for(int j = 0; j < columns; ++j)
        {
            numbers[i][j] = i * columns + j + 1;
        }
    }

    PrintMatrixClockwisely(numbers, columns, rows);
    printf("
");

    for(int i = 0; i < rows; ++i)
        delete[] (int*)numbers[i];

    delete[] numbers;
}

int main(int argc, char** argv)
{
    /*
    1
    */
    Test(1, 1);

    /*
    1    2
    3    4
    */
    Test(2, 2);

    /*
    1    2    3    4
    5    6    7    8
    9    10   11   12
    13   14   15   16
    */
    Test(4, 4);

    /*
    1    2    3    4    5
    6    7    8    9    10
    11   12   13   14   15
    16   17   18   19   20
    21   22   23   24   25
    */
    Test(5, 5);

    /*
    1
    2
    3
    4
    5
    */
    Test(1, 5);

    /*
    1    2
    3    4
    5    6
    7    8
    9    10
    */
    Test(2, 5);

    /*
    1    2    3
    4    5    6
    7    8    9
    10   11   12
    13   14   15
    */
    Test(3, 5);

    /*
    1    2    3    4
    5    6    7    8
    9    10   11   12
    13   14   15   16
    17   18   19   20
    */
    Test(4, 5);

    /*
    1    2    3    4    5
    */
    Test(5, 1);

    /*
    1    2    3    4    5
    6    7    8    9    10
    */
    Test(5, 2);

    /*
    1    2    3    4    5
    6    7    8    9    10
    11   12   13   14    15
    */
    Test(5, 3);

    /*
    1    2    3    4    5
    6    7    8    9    10
    11   12   13   14   15
    16   17   18   19   20
    */
    Test(5, 4);

    return 0;
}