Classic 150 Interview Questions P201 Bitwise AND of Numbers Range

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Timeline

Timeline

2025-11-25

init

Bit manipulation

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Problem:

P201 Bitwise AND of Numbers Range

https://leetcode.cn/problems/bitwise-and-of-numbers-range/description/?envType=study-plan-v2&envId=top-interview-150

Find the common binary prefix and then shift it back to the left.

class Solution {
    public:
	int rangeBitwiseAnd(int left, int right)
	{

		int shift = 0;
		while (left < right) {
			left = left >> 1;
			right = right >> 1;
			shift++;
		}

		return right << shift;
	}
};