Problem:
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.
思路：
Solution (C++):
char findTheDifference(string s, string t) {
vector<int> vec(26, 0);
int i = 0;
int m = s.length(), n = t.length();
for (i = 0; i < m; ++i) {
++vec[s[i]-'a'];
}
for (i = 0; i < n; ++i) {
--vec[t[i]-'a'];
}
for (i = 0; i < 26; ++i) {
if (vec[i] == -1) break;
}
return char(int('a')+i);
}
性能：
Runtime: 4 ms Memory Usage: 6.9 MB
思路：
Solution (C++):
性能：
Runtime: ms Memory Usage: MB
