题解

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