方法1:位运算
时间复杂度:$O(s + t)$
空间复杂度:$O(1)$
解题思路
异或运算有交换律。参考:
https://leetcode.cn/problems/single-number/solution/zhi-chu-xian-yi-ci-de-shu-zi-by-leetcode-solution/
本题解析:
https://leetcode.cn/problems/find-the-difference/solution/zhao-bu-tong-by-leetcode-solution-mtqf/
Java 代码
class Solution {
public char findTheDifference(String s, String t) {
int res = 0;
for (int i = 0; i < s.length(); i ++) {
res ^= s.charAt(i);
}
for (int i = 0; i < t.length(); i ++) {
res ^= t.charAt(i);
}
return (char)res;
}
}