输入输出 + 逻辑分析 + 循环语句

#include<bits/stdc++.h>
using namespace std;
int main(){
    int n;
    cin>>n;
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n-i;j++){
            cout<<" ";
        }
        cout<<"*";
        for(int j=1;j<=i*2-3;j++){
            cout<<" ";
        }
        if(i!=1) cout<<"*";
        cout<<endl;
    }
    for(int i=n-1;i>=1;i--){
        for(int j=1;j<=n-i;j++){
            cout<<" ";
        }
        cout<<"*";
        for(int j=1;j<=i*2-3;j++){
            cout<<" ";
        }
        if(i!=1) cout<<"*";
        cout<<endl;
    }
    return 0;
}