190. Reverse Bits

📝 Problem Details

• Title: 190. Reverse Bits
• Link: https://leetcode.com/problems/reverse-bits/
• Difficulty: Easy
• Tags/Categories: Bit-Manipulation

reverse bits of a given 32 bits unsigned integer

💡 Explanation of Solution

- initialize result as 0
- for each of the 32 bits
	- shift the result to the left by 1 to make room for the next bit 
	- take the last bit of n(n&1) and add it to the result
	- then shift n to the right by 1 to move to the next bit 

⌛ Complexity Analysis

Time Complexity: O(32) ~ O(1)
Space Complexity: O(1)

💻 Implementation of Solution

class Solution {
public:
    uint32_t reverseBits(uint32_t n) {
        uint32_t result = 0;
 
        for (int i = 0; i < 32; i++) {
            result <<= 1;        // Make space for the next bit
            result |= (n & 1);   // Add the last bit of n
            n >>= 1;             // Drop the last bit from n
        }
 
        return result;
    }
};