1 class Solution {
2 public:
3 int getNum(char c){
4 if (c>='a' && c<='z')
5 return c-'a';
6 if (c>='A' && c<= 'Z')
7 return c-'A';
8 if (c>='0' && c<='9')
9 return 30 + (c-'0');
10 return -1;
11 }
12 bool isPalindrome(string s) {
13 // IMPORTANT: Please reset any member data you declared, as
14 // the same Solution instance will be reused for each test case.
15 int len = s.length();
16 int i =0, j = len-1;
17 while (i<j && i<len && j>=0){
18 char x = s.at(i);
19 int a = getNum(x);
20 if (a==-1){
21 i++;
22 continue;
23 }
24 char y = s.at(j);
25 int b = getNum(y);
26 if (b==-1){
27 j--;
28 continue;
29 }
30 if (a!=b)
31 return false;
32 i++;
33 j--;
34 }
35 return true;
36 }
37 };
