SumofEvenNumbers.cpp

// Q. Given a number N, print sum of all even numbers from 1 to N.
/*
	Pre-requisite to solve this problem:
	In this question, we have to find sum of all even numbers till n. To take sum of all the even numbers, we have to take a variable and initialize it to zero. Let us name this variable as sum. 
	Following code is used to add 2 to sum variable and update it to the same sum variable:
	sum = sum + 2 
	
	Hint to solve this problem: We will have to loop on even numbers only and add the even numbers to the same sum variable, described above.
*/  


#include<iostream>
using namespace std;


int main(){
	int N, i=0, sum=0;
	cin>>N;
	while (i <= N){
		sum = sum+i;
		i = i+2;
	}
	cout<<sum<<endl;
}