Day 6: Bitwise Operators :- 10 Days Of Javascript HackerRank Solution

Problem:-

Objective

Today, we're practicing bitwise operations. Check the attached tutorial for more details.

Task

We define  to be a sequence of distinct sequential integers from  to ; in other words, . We want to know the maximum bitwise AND value of any two integers,  and  (where ), in sequence  that is also less than a given integer, .

Complete the function in the editor so that given  and , it returns the maximum .

Note: The  symbol represents the bitwise AND operator.

Input Format

The first line contains an integer, , denoting the number of function calls.
Each of the  subsequent lines defines a dataset for a function call in the form of two space-separated integers describing the respective values of  and .

Constraints

Output Format

Return the maximum possible value of  for any  in sequence .

Sample Input 0

3
5 2
8 5
2 2

Sample Output 0

1
4
0

Explanation 0

We perform the following  function calls:

1. When  and , we have the following possible  and  values in set :
   The maximum of any  that is also  is , so we return .
2. When  and , the maximum of any  in set  is  (see table above), so we return .
3. When  and , the maximum of any  in set  is  (see table above), so we return .

Sample Input 1

2
9 2
8 3

Sample Output 1

1
2

Explanation 1

We perform the following  function calls:

1. When  and , the maximum of any  in set  is  (see table above), so we return .
2. When  and , the maximum of any  in set  is  (see table above), so we return .

Solution:-

'use strict';

process.stdin.resume();

process.stdin.setEncoding('utf-8');

let inputString = '';

let currentLine = 0;

process.stdin.on('data', inputStdin => {

inputString += inputStdin;

});

process.stdin.on('end', _ => {

inputString = inputString.trim().split('\n').map(string => {

return string.trim();

});

main();

});

function readLine() {

return inputString[currentLine++];

}

function getMaxLessThanK(n, k) {

let max_anb = 0;

for (let b = n; b > 0; b--) {

for (let a = b - 1; a > 0; a--) {

if ((a & b) < k && (a & b) > max_anb) {

max_anb = (a & b);

}

}

}

return max_anb;

}

function main() {

const q = +(readLine());

for (let i = 0; i < q; i++) {

const [n, k] = readLine().split(' ').map(Number);

console.log(getMaxLessThanK(n, k));

}

}