
Bit Manipulation
Question
The Hamming distance between two integers is the number of positions at which the corresponding bits are different.
Given two integers x and y, calculate the Hamming distance.
Note:
0 ≤ x, y < 231.
Example:
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Input: x = 1, y = 4 Output: 2 Explanation: 1 (0 0 0 1) 4 (0 1 0 0) ↑ ↑ The above arrows point to positions where the corresponding bits are different.
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My Answer
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class { public int hammingDistance(int x, int y) { int temp = x^y; int res = 0; while(temp!=0){ temp = temp & (temp-1); res++; } return res; } }
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Running time: 12ms
Simpler Answer
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class { public int hammingDistance(int x, int y) { return Integer.bitCount(x ^ y); } }
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Running time: 12ms
BitCount
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int res=0; while(num!=0){ num = num & (num-1); res++; }
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