PrintMatrixClockwisely.cpp

// 29 顺时针打印矩阵
#include <cstdio>

void printNumber(int number)
{
    printf("%d\t", number);
}
void PrintMatrixInCircle(int** numbers, int columns, int rows, int start)
{
    // 4*4 1开始 2结束
    int endX = columns - 1 - start;
    int endY = rows - 1 - start;

    //从左到右的第一行
    for (int i = start; i <= endX; i++) {
        int number = numbers[start][i];
        printNumber(number);
    }

    //从上到下
    if (start < endY) {
        for (int i = start + 1; i <= endY; i++) {
            int number = numbers[i][endX];
            printNumber(number);
        }
    }

    // 从右到左
    if (start < endX && start < endY) {
        for (int i = endX - 1; i >= start + 1; --i) {

            int number = numbers[endY][i];
            printNumber(number);
        }
    }

    // 从下到上
    if (start < endX && start < endY - 1) {
        for (int i = endY - 1; i >= start + 1; --i) {

            int number = numbers[i][start];
            printNumber(number);
        }
    }
}

void PrintMatrixClockwisely(int** numbers, int columns, int rows)
{
    if (!numbers || columns <= 0 || rows <= 0) {
        return;
    }

    int start = 0;

    while (columns > start * 2 && rows > start * 2) {
        PrintMatrixInCircle(numbers, columns, rows, start);
        ++start;
    }
}