View Code of Problem 18

#include<iostream>
using namespace std;
int main(){
	int a[10000]={0};
	a[3]=1;a[4]=2;
	int x=2;
	for(int i=5;i<10000;i++){
		a[i]=a[i-1]+x;
		if(i%2==0){
			x++;
		}
	}
	int n;
	while(scanf("%d",&n)!=EOF){
		printf("%d\n",a[n]);
	}
}