hdu 1396 Counting Triangles

#include<iostream>
using namespace std;
int dp[501]={0};
int main()
{
dp[1]=1;
int i;
for(i=2;i<=500;i++)
{
if(i%2){dp[i]=dp[i-1]+(i*i-1)/4+i*(i+1)/2;}
else{dp[i]=dp[i-1]+(i*i)/4+i*(i+1)/2;}
}
int n;
while(cin>>n)
{
cout<<dp
<<endl;
}
return 0;
}