算法题：矩阵旋转90度

#include <iostream>
#include <iomanip>
using namespace std;
void Grial(int (*a)[5],int n)
{
    //数组顺时针旋转90度。
    //边界值的考虑让我小小的思考了一下。
    int temp;
    int startX = 0;
    int startY = 0;
    int j = 0;
    while (startX < n/2)
    {
        startX = j;
        for (int i = j; i < n - j-1; i++)
        {
            startY = i;
            //不开辟空间，仅仅交换数据就可以轻松的做到。
            temp = a[startX][startY];
            a[startX][startY] = a[n - startY - 1][startX];
            a[n - startY - 1][startX] = a[n - startX - 1][n - startY - 1];
            a[n - startX - 1][n - startY - 1] = a[startY][n - startX - 1];
            a[startY][n - startX - 1] = temp;
        }
        j++;
    }
}
int main()
{
    int a[][5] = {
                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
                };
    Grial(a,5);
    for (int i = 0; i < 5; i++)
    {
        for (int j = 0; j < 5; j++)
        {
            cout << setw(4) << a[i][j];
        }
        cout << endl;
    }
    cout << endl;

}