LeetCode OJ - Single Number (improve)(C++)(try 1 time)

為了練習尋找實習時會碰到的問題，我用別人推薦的 LeetCode online judge。
希望能直接寫程式，不用事先編譯就能直接AC。
下面是我寫的  Single Number 的解法。
這是改良後的版本，這邊是舊版本。
執行時間為 O(n), 並且沒用到額外記憶體!

To practice future interview question, I use LeetCode online judge.
I am trying to type code directly on website without compile in other tool.
The following program is my Single Number solution.
It's a improved version. See the older version here.
Time complexity is O(n), ans I implement it without using extra memory.

嘗試次數 Try number: 1
是否事先在其他工具編譯 if compile first in other tool: No
使用的程式語言 using programming language: C++
以前是否看過 seen this problem before: No

點這裡看題目 Click here to see this Problem!

	//see the discussion, then I improve the method
	class Solution {
	public:
	int singleNumber(int A[], int n) {
	/*
	if we XOR same number, the result will be 0. Ex: 3 ^ 3 = 0
	if we XOR any number with zero, the result will be that number. Ex: 3 ^ 0 = 3
	so we can XOR all element, the element which appears twice will counterbalance to 0.
	Then left the element appears only once.
	*/
	for(int i = 1; i < n; i++)
	A[0] ^= A[i];
	return A[0];
	}
	};

view raw LeetCode OJ - Single Number (improve) (C++) .cpp hosted with ❤ by GitHub

Please feel free to use it after adding this blog as an reference. (http://autekroy.blogspot.tw) If there is any mistake or comment, please let me know. :D 

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