190-颠倒二进制位

LeetCode 190. Reverse Bits

LeetCode-190

Reverse bits of a given 32 bits unsigned integer.

Example 1:

Input: n = 00000010100101000001111010011100
Output:    964176192 (00111001011110000010100101000000)
Explanation: The input binary string 00000010100101000001111010011100 represents the unsigned integer 43261596, so return 964176192 which its binary representation is 00111001011110000010100101000000.

method

先左移再加上取出来的位，不能反过来

uint32_t reverseBits(uint32_t n) {
    uint32_t res = 0;
    for (int i = 0; i < 32; i++) {
        res <<= 1;
        res += ((n >> i) & 1);
    }
    return res;
}