就是入门

#include<iostream>
using namespace std;
int n;
void print(){
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n-i;j++){
            cout<<"*";
        }
        int p=n-1;
        for(int j=1;j<=i;j++){
            cout<<p;
            p--;
        }
        p++;
        for(int j=1;j<=i-1;j++){
            p++;
            cout<<p;
        }
        for(int j=1;j<=n-i;j++){
            cout<<"*";
        }
        cout<<endl;
    }
    for(int i=n-1;i>=1;i--){
        for(int j=1;j<=n-i;j++){
            cout<<"*";
        }
        int p=n-1;
        for(int j=1;j<=i;j++){
            cout<<p;
            p--;
        }
        p++;
        for(int j=1;j<=i-1;j++){
            p++;
            cout<<p;
        }
        for(int j=1;j<=n-i;j++){
            cout<<"*";
        }
        cout<<endl;
    }
}
int main(){
    cin>>n;
    print();
}