Playing With Bits.cpp

/* Hacker Blocks */
/* Title - Playing With Bits */
/* Created By - Akash Modak */
/* Date 7/1/2020 */

// Prateek Bhayia likes to play with bits. One day Prateek bhayia decides to assign a task to his student Sanya. You have help Sanya to complete this task. Task is as follows - Prateek Bhayia gives Q queries each query containing two integers a and b. Your task is to count the no of set-bits in for all numbers between a and b (both inclusive)

// Input Format
// Read Q - No of Queries, Followed by Q lines containing 2 integers a and b.

// Constraints
// Q,a,b are integers.

// Output Format
// Q lines, each containing an output for your query.

// Sample Input
// 2
// 1 1
// 10 15
// Sample Output
// 1
// 17

#include<iostream>
using namespace std;
int countSetBits(int n){
	int ans=0;
	while(n>0){
		if(n&1==1)
		ans++;
		n=n>>1;
	}
	return ans;
}
int main() {
	int q,a,b;
	cin>>q;
	while(q--){
		cin>>a>>b;
		int count =0;
		for(int i=a;i<=b;i++){
			count+= countSetBits(i);
		}
		cout<<count<<endl;
	}
	return 0;
}