[LeetCode] 389. Find the Difference

轉自LeetCode

Given two strings s and t which consist of only lowercase letters.

String t is generated by random shuffling string s and then add one more letter at a random position.

Find the letter that was added in t.

Example:

Input:
s = "abcd"
t = "abcde"

Output:
e

Explanation:
'e' is the letter that was added.

<Solution>

跟 268. Missing Number 概念一樣，可以使用 XOR來找

不同的是，一個是要找少哪一個，這一次要找多哪一個

code 如下

C++

	class Solution {
	public:
	char findTheDifference(string s, string t) {
	const int len = s.length();
	char c = t.back();
	for(int i = 0; i < len; i++) {
	c ^= s[i];
	c ^= t[i];
	}
	return c;
	}
	};

view raw findExtraChar.cpp hosted with ❤ by GitHub

kotlin

	class Solution {
	fun findTheDifference(s: String, t: String): Char {
	var ans = t.last().toInt()
	for(i in s.indices) {
	ans = ans xor s[i].toInt()
	ans = ans xor t[i].toInt()
	}
	return ans.toChar()
	}
	}

view raw find_the_difference.kt hosted with ❤ by GitHub