题解 | 空心正方形图案

#include <stdio.h>

int main() {
    int n = 0;
    while (scanf("%d",&n) != EOF) 
    {
        char arr[n][n];
        for (int i = 0; i < n; i++) 
        {

            for (int j = 0; j < n; j++) 
            {
                arr[i][j] = ' ';
                arr[0][j] = '*';
                arr[n - 1][j] = '*';
                arr[i][0] = '*';
                arr[i][n - 1] = '*';
                printf("%c ",arr[i][j]);
            }
            printf("\n");      
        }
    }
    return 0;
}