题解(求点赞)

#include<iostream>
using namespace std;
int x,y;
int main()
{
    int n;
    cin>>n;
    int x=n-1,y=3;
    while(1)
	{
        if(x>=y*2)
		{
            x-=y*2;
        }
		else
		{
            y-=2;
            break;
        }
        y+=2;
    }
    for(int i=y;i>=1;i-=2)
	{
   		for(int j=1;j<=(y-i)/2;j++)
    	    cout<<" ";
  	    for(int j=1;j<=i;j++)
    	    cout<<"*";
   		for(int j=1;j<=(y-i)/2;j++)
    	    cout<<" ";
        cout<<"\n";
    }
    for(int i=3;i<=y;i+=2)
	{
   		for(int j=1;j<=(y-i)/2;j++)
    	    cout<<" ";
  	    for(int j=1;j<=i;j++)
    	    cout<<"*";
   		for(int j=1;j<=(y-i)/2;j++)
    	    cout<<" ";
        cout<<"\n";
    }
    cout<<x;
    return 0;
}