Write a function that takes an unsigned integer and returns the number of ’1‘ bits it has (also known as the Hamming weight).
For example, the 32-bit integer ’11‘ has binary representation 00000000000000000000000000001011
, so the function should return 3.
位运算,找出int型数字为1的位的个数。因为是32位,外层循环有32次,但是一旦循环过的位数最大值大于当前值,就停止运算,因为之后的左移运算,全为0
int hammingWeight(uint32_t n) { int result = 0; int cursor = 1; for(int i = 1; i <= 32; i++) { if( (n & cursor) != 0) { result++; } cursor = cursor << 1; if(pow(2,i) - 1 >= n) { break; } } return result; }
时间: 2024-11-08 01:20:39