题解

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

		cout <<"*";
	for(int j=1;j<=n;j++){
		cout <<" ";
	}
	if(i!=a-1){
		cout <<"*";
	}
	d++;
	cout <<endl;
	n-=2;
}
	return 0;
}