真六

想必很多人是复制题解的吧。（那必须的）
开个玩笑

#include <iostream>
using namespace std;

int main(){
    int n;
    cin >> n;
    for(int i = 1;i <= n;i++){
        for(int j = 0;j < (n-i);j++){
            cout << " ";
        }
        cout << "*";
        for(int j = 1;j < i*2-2;j++){
            cout << " ";
        }
        if(i != 1){
            cout << "*" <<endl;
        }else{
            cout << endl;
        }
    }
    for(int i = n-1;i >0;i--){
        for(int j = 0;j < (n-i);j++){
            cout << " ";
        }
        cout << "*";
        for(int j = 1;j < i*2-2;j++){
            cout << " ";
        }
        if(i != 1){
            cout << "*"<< enumdl;
        }else{
            cout << endl;
        }
    }
    return 0;
}