求帮：能否优化这段c++代码
每次更改都很麻烦能否实现输入一个n然后输出n行啊
#include<iostream>
using namespace std;
int main()
{
cout<<" *";
cout<<" ***";
cout<<" *****";
cout<<"*******";
}
#include<bits/stdc++.h>
using namespace std;
int main()
{
int n;
cin>>n;
for(int i=n;i>=1;i--)
{
for(int j=1;j<=i-1;j++)
{
cout<<" ";
}
for(int j=1;j<=(n-i+1)*2-1;j++)
{
cout<<"*";
}
cout<<endl;
}
}