[LeetCode] 190. Reverse Bits

轉自LeetCode

Reverse bits of a given 32 bits unsigned integer.

For example, given input 43261596 (represented in binary as 00000010100101000001111010011100), return 964176192 (represented in binary as 00111001011110000010100101000000).

<Solution>
按照題意，一個一個把 bit 給 reverse 即可

code 如下

	class Solution {
	public:
	uint32_t reverseBits(uint32_t n) {
	uint32_t ans = 0;
	for(int i = 0; i < 32; i++) {
	ans |= ((n >> i) & 0x1) << (31 - i);
	}
	return ans;
	}
	};

view raw reverseBits.cpp hosted with ❤ by GitHub

Kotlin

	class Solution {
	// you need treat n as an unsigned value
	fun reverseBits(n:Int):Int {
	var ans = 0
	for(i in 0..31) {
	ans = ans shl 1
	if((n and (1 shl i)) != 0) {
	ans = ans or 1
	}
	}
	return ans
	}
	}

view raw reverse_bits.kt hosted with ❤ by GitHub