LeetCode: Valid Palindrome

基本一次过吧，题目没说数字要算进去啊。。

 1 class Solution {
 2 public:
 3     bool check(string t) {
 4         for (int i = 0; i < t.size(); i++) {
 5             if (t[i] != t[t.size()-1-i]) return false;
 6         }
 7         return true;
 8     }
 9     bool isPalindrome(string s) {
10         // Start typing your C/C++ solution below
11         // DO NOT write int main() function
12         string t;
13         for (int i = 0; i < s.size(); i++) {
14             if (s[i] >= 'A' && s[i] <= 'Z') t += (s[i] + 'a' - 'A');
15             if (s[i] >= 'a' && s[i] <= 'z') t += s[i];
16             if (s[i] >= '0' && s[i] <= '9') t += s[i];
17         }
18         return check(t);
19     }
20 };