题解 | 箭形图案

#include <stdio.h>
int main() {
    int a = 0;
    int i = 0;
    int j = 0;
    int count = 0;
    while (scanf("%d", &a) != EOF) {
        count = 2 * a;
        for (i = 1; i <= a + 1; i++) {
            for (j = 1; j <= count; j++) {
                printf(" ");
            }
            for (j = 1; j <= i; j++) {
                printf("*");
            }
            count -= 2;
            printf("\n");
        }//打印上半部分
        for (int i = 1; i <= a; i++) {
            for (j = 1; j <= 2 * i; j++) {
                printf(" ");
            }
            for (j = 1; j <= (a + 1) - i; j++) {
                printf("*");
            }
            printf("\n");//下半部分的打印
        }

    }


    return 0;
}