package LeetCode_1318 /** * 1318. Minimum Flips to Make a OR b Equal to c * https://leetcode.com/problems/minimum-flips-to-make-a-or-b-equal-to-c/description/ * * Given 3 positives numbers a, b and c. * Return the minimum flips required in some bits of a and b to make ( a OR b == c ). (bitwise OR operation). Flip operation consists of change any single bit 1 to 0 or change the bit 0 to 1 in their binary representation. Example 1: Input: a = 2, b = 6, c = 5 Output: 3 Explanation: After flips a = 1 , b = 4 , c = 5 such that (a OR b == c) * */ class Solution { fun minFlips(a: Int, b: Int, c: Int): Int { var count = 0 var a_ = a var b_ = b var c_ = c while (a_ > 0 || b_ > 0 || c_ > 0) { //get the lowest bit val a0 = a_ and 1// a_ and 1 ==> a_ % 2 val b0 = b_ and 1 val c0 = c_ and 1 //if current bit of c is 1 and a,b if 0, need flip one time if (c0 == 1) { if (a0 == 0 && b0 == 0) { count++ } } else { //if current bit of c is 0: //if current bit of a or b is 1, need flip one time, //if current bit of a and b is 1, need flip two times, count += a0 + b0 } a_ = a_ shr 1 b_ = b_ shr 1 c_ = c_ shr 1 } return count } }