1318. Minimum Flips to Make a OR b Equal to c

Given 3 positives numbers ab 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)

Example 2:

Input: a = 4, b = 2, c = 7
Output: 1

Example 3:

Input: a = 1, b = 2, c = 3
Output: 0
class Solution {
    public int minFlips(int a, int b, int c) {
        int res = 0;
        for(int i = 0; i < 31; i++, a = a >> 1, b = b >> 1, c = c >> 1 ){
            int t = a & 1;
            int m = b & 1;
            int n = c & 1;
            if ((t | m) != n) {
                if (n == 0) {
                    if (t == 1) {
                        res++;
                    }
                    if (m == 1) {
                        res++;
                    }
                } else {
                    res++;
                }
            }
        }
        return res; 
    }
}

来自https://leetcode.com/problems/minimum-flips-to-make-a-or-b-equal-to-c/discuss/477683/Java-Bit

a|b反转多少位等于c,每个数是32位,总共可以翻31次。在每一位上判断和c的关系,如果不相等就继续判断,

1.c是0,a|b不是接着往下判断,可能翻转1位或2位

2. c是1,a|b不是,此时翻转一位即可

原文地址:https://www.cnblogs.com/wentiliangkaihua/p/12190356.html