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2014-10-20 11:23:39 +08:00
// Source : https://oj.leetcode.com/problems/valid-palindrome/
// Author : Hao Chen
// Date : 2014-06-26
/**********************************************************************************
*
* Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases.
*
* For example,
* "A man, a plan, a canal: Panama" is a palindrome.
* "race a car" is not a palindrome.
*
* Note:
* Have you consider that the string might be empty? This is a good question to ask during an interview.
*
* For the purpose of this problem, we define empty string as valid palindrome.
*
*
**********************************************************************************/
2014-10-20 11:23:39 +08:00
class Solution {
public:
bool isPalindrome(string s) {
s = removeNoise(s);
for(int i=0; i<s.size()/2; i++){
if (s[i]!= s[s.size()-i-1]){
return false;
}
}
return true;
}
string removeNoise(string& s){
string d;
for(int i=0; i<s.size(); i++){
if(::isalpha(s[i]) || ::isdigit(s[i])){
d.push_back(::tolower(s[i]));
}
}
return d;
}
};