OK了呀

#include<bits/stdc++.h>
using namespace std;
int main(){
    int n; cin >> n;
    for(int i = 1;i <= n + 1;i++){
        for(int j = 1;j <= i;j++) cout << "* ";
        cout << endl;
    }
    for(int i = n;i >= 1;i--){
        for(int j = 1;j <= i;j++) cout << "* ";
        cout << endl;
    }
    return 0;
}