【图形】晕

看着这样的"回”形图案你晕吗？来做出它。

输入：
    n。正方形的边长

输出：
    边长为 n 的数字回形方阵。

代码如下

#define _CRT_SECURE_NO_WARNINGS 1    
#include <stdio.h>
void outer_frame(int start, int end, int a, int num_sq[][10]);
int main(void)
{
    int a = 1;
    int* p_a = &a;
    int x = 0, y = 0;
    int n;
    scanf("%d", &n);
    int num_sq[10][10] = {0};
    int start = 0, end = n - 1;
    
    outer_frame(start, end, a,num_sq);

    int counter = 0;
    for (x = 0; x < n; x++) {
        for (y = 0; y < n; y++) {
            printf("%3d", num_sq[x][y]);
            counter++;
            if ((counter % n == 0) && (counter!=n*n))
                putchar('\n');
        }            
    }
    return 0;
}
void outer_frame(int start, int end, int a,int num_sq[][10]) {
    int x = 0, y = 0;
    for (x = start, y = start; y < end+1; y++) {
        num_sq[x][y] = a++;
        //printf("num_sq[%d][%d] = %3d\n", x, y, num_sq[x][y]);
    }
    for (y = end, x = start+1; x < end+1; x++) {
        num_sq[x][y] = a++;
        //printf("num_sq[%d][%d] = %3d\n", x, y, num_sq[x][y]);
    }
    for (x = end, y = end-1; y > start; y--) {
        num_sq[x][y] = a++;
        //printf("num_sq[%d][%d] = %3d\n", x, y, num_sq[x][y]);
    }
    for (x = end, y = start; x > start; x--) {
        num_sq[x][y] = a++;
        //printf("num_sq[%d][%d] = %3d\n", x, y, num_sq[x][y]);
    }
    start += 1; end -= 1;
    if (end > 0)
        outer_frame(start, end, a, num_sq);
}