题解 | 回型矩阵

#include <stdio.h>

int main() {
    int n = 0; 
    scanf("%d", &n); 
    int left = 0 ; 
    int top = 0; 
    int num = 1; 
    int right = n - 1; 
    int buttom = n - 1;
    int arr[1000][1000] = {0};
    
    while(num <= n * n)
    {
        for (int i = left; i <= right; i++)
        {
            arr[top][i] = num++; 
        }
        top++; 
        
        for (int j = top; j <= buttom; j++)
        {
            arr[j][right] = num++;
        }
        right--; 
        
        for (int k = right; k >= left; k--)
        {
            arr[buttom][k] = num++;
        }
        buttom--; 
        
        for (int p = buttom; p >= top; p--)
        {
            arr[p][left] = num++;
        }
        left++; 
        
    }

    for (int i = 0; i < n; i++)
        {
            for (int j = 0; j < n; j++)
            {
                printf("%d ", arr[i][j]);
            }
            printf("\n");
        }

    return 0;
}