Bitwise Operation || JS Hackerrank Solution

 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){            var c=0;      for(var i=n;i>0;i--){          for(var j=i-1;j>0;j--){              if((i&j)<k && (i&j)>c){                  c=(i&j);              }          }      }      return c;         }     function main() {     const q = +(readLine());          for (let i = 0; i < q; i++) {         const [n, k] = readLine().split(' ').map(Number);                  console.log(getMaxLessThanK(n, k));      } }