hdu 2091 空心三角形

#include<iostream>using namespace std;int main(){int n;char a;int flag=0;while(cin>>a>>n&&(a!='@')){if(flag)cout<<endl;flag=1;for(int i=1;i<n;i++)cout<<" ";cout<<a<<endl;for(int i=2;i<n;i++){for(int j=1;j<=n-i;j++)cout<<" ";cout<<a;for(int j=1;j<=2*i-3;j++)cout<<" ";cout<<a<<endl;}if(n!=1){for(int i=1;i<=2*n-1;i++)    cout<<a;    cout<<endl;}}return 0;}