题解 | #箭形图案#

#include <stdio.h>

int main() {
    int n;
    while (scanf("%d", &n) != EOF) {
        int i = 0;
        int j = 0;
        int k = 0;
        int l = 0;
        int a = 0;
        for (i = 1; i <= 2 * n + 1; i++) {
            if (i <= n + 1) {
                for (j = n; j >= i; j--) {
                    printf("  ");
                }
                for (k = 1; k <= i; k++) {
                    printf("*");
                }
                printf("\n");
            }
            else
            {
                for(l=1;l<=i-n-1;l++)
                {
                    printf("  ");
                }
                for(a=n;a>=i-n-1;a--)
                {
                    printf("*");
                }
                printf("\n");
            }
        }
    }
    return 0;
}