Single Number I
Given an array of integers, every element appears twice except for one.
Find that single one.
Your algorithm should have a linear runtime complexity.
Could you implement it without using extra memory?
Solution: XOR.
1 class Solution { 2 public: 3 int singleNumber(int A[], int n) { 4 int single = 0; 5 for(int i = 0; i < n; i++) { 6 single ^= A[i]; 7 } 8 return single; 9 } 10 };