LeetCode 389. Find the Difference(找不同)
题目描述
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.
解法一
思路
这题换一个说法就似曾相识了:一个数组中,除一个数仅出现一次外,其他数都出现两次,找出这个数。没错,就是LeetCode 136. Single Number(只出现一次的数),这里把每个字母当成一个数组元素就好了(实际上char
就可以等价地看作int
)。
Python
class Solution(object):
def findTheDifference(self, s, t):
"""
:type s: str
:type t: str
:rtype: str
"""
result_ord = 0
for item in s:
result_ord ^= ord(item)
for item in t:
result_ord ^= ord(item)
return chr(result_ord)
Java
public class Solution {
public char findTheDifference(String s, String t) {
char result = 0;
for (char item : s.toCharArray()) {
result ^= item;
}
for (char item : t.toCharArray()) {
result ^= item;
}
return result;
}
}
C++
class Solution {
public:
char findTheDifference(string s, string t) {
char result = 0;
for (char item : s) {
result ^= item;
}
for (char item : t) {
result ^= item;
}
return result;
}
};