Through Leetcode learning bit arithmetic and its go implementation

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Problem description

461. Hamming Distance
That is, the number of binary corresponding digits of two positive integers is different.

Principle explanation

In terms of the problem description, the most intuitive solution is that the decimal number is first turned into binary, and then the same number is the same, different counters accumulate, the value of the final counter is Hamming Distance .

Optimization scheme: First ^ operation, the number of bits of the result of the operation to traverse, 1 the counter accumulated

Based on this idea, there is a need to use the 异或运算 and 位运算 .

Xor ^ and XOR or non-

XOR algorithm: The same is zero, the difference is one.
XOR algorithm: The same as one, the difference is zero.
That

输入A： 1 0 1 0输入B： 1 1 0 0异或运算结果： 0 1 1 0异或非(同或)运算结果：1 0 0 1

Move left << and right >>

Move left

• The right-hand vacated bits are filled with 0
• High-left-shift overflow discards the high

Move right

• The left vacated bits are filled with 0 or 1. Positive numbers are filled with 0, negative numbers are filled with 1
• The low-right-shift overflow discards the bit

Code implementation

func hammingDistance(x int, y int) int {    counter := 0    tmp := x ^ y    t := 1        for i := uint(0); i < 32 && t > 0; i++ {        t = tmp >> i        counter += (tmp >> i) & 1    }    return counter}

Reference

1. Baidu Wikipedia or not
2. Baidu Encyclopedia Bit arithmetic