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).
Follow up: If this function is called many times, how would you optimize it?
Related problem: Reverse Integer
难度系数:
容易
实现
uint32_t reverseBits(uint32_t n) {
static uint32_t key = 0;
static uint32_t val = 0;
if (n == key) return val;
if (n == val) return key;
uint32_t ret = 0;
int index = 31;
key = n;
while (n > 0) {
ret |= (n & 0x1) << index;
n >>= 1;
index--;
}
val = ret;
return val;
}
时间: 2024-11-05 23:27:13