# Maximum Bitwise AND pair from given range in C++

C++Server Side ProgrammingProgramming

## Problem statement

Given a range [L, R], the task is to find a pair (X, Y) such that L ≤ X < Y ≤ R and X & Y is maximum among all the possible pairs then print the bitwise AND of the found pair.

## Example

If L = 1 and R = 10 then maximum bitwise AND value is 8 which can be formed as follows −

1000 # Binary representation of 8
Bitwise AND
1001 # Binary representation of 9
----
1000 # Final result

## Algorithm

Iterate from L to R and check the bitwise AND for every possible pair and print the maximum value in the ends

## Example

Let us now see an example −

Live Demo

#include <bits/stdc++.h>
using namespace std;
int getMaxBitwiseAndValue(int L, int R) {
int maxValue = L & R;
for (int i = L; i < R; ++i) {
for (int j = i + 1; j <= R; ++j) {
maxValue = max(maxValue, (i & j));
}
}
return maxValue;
}
int main() {
int L = 1, R = 10;
cout << "Maximum value = " << getMaxBitwiseAndValue(L, R) << endl;
return 0;
}

## Output

Maximum value = 8