#include using namespace std; int main() { //如果要求输入的是9行,那么n=(9+1)/2=5 int i, j, n = 5; for (i = 1; i <= n; i++) { for (j = 1; j <= (n - i); j++) cout << " "; for (j = 1; j <= (2 * (i - 1) + 1); j++) cout << "*"; cout << endl; } for (i = n - 1; i >= 1; i--) { for (j = 1; j <= (n - i); j++) cout << " "; for (j = 1; j <= (2 * (i - 1) + 1); j++) cout << "*"; cout << endl; } cout << endl; return 0; }