Leetcode: signal_number

I. Question: This question is to give you an array. Two of the numbers are the same and can be said to be paired. There is only one exception. So the question is to find the number of bachelors (signal number)

Ii. Analysis: in this case, it means no additional memory can be used, and the complexity of linear O (n) is actually skillful. Bit operations (^)

For example:

Array [5] = {2, 4, 4, 2}

010

100

011

100

^ 010

-----------

= 011

Therefore, the solution is available.

class Solution {public:    int singleNumber(int A[], int n) {        // Note: The Solution object is instantiated only once and is reused by each test case.        int flag = 0;        while(n){            flag ^= A[n];        }        return flag;    }};

Leetcode: signal_number