递推,找规律
#include <iostream> #include <cstdio> using namespace std; int count[510]; int main() { count[1]=1; int i,j; for(i=2;i<=500;i++) { int t=count[i-1]; for(j=1;j<=i;j++) t=t+i+1-j; for(j=1;i-j>=j;j++) t=t+i-j+1-j; count[i]=t; } int n; while(cin>>n) cout<<count[n]<<endl; return 0; }