125. Valid Palindrome - easy
문제
Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases.
Note: For the purpose of this problem, we define empty string as valid palindrome.
제한사항
- s consists only of printable ASCII characters.
입출력 예
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Example 1:
Input: "A man, a plan, a canal: Panama"
Output: true
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Example 2:
Input: "race a car"
Output: false
풀이
- String
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class Solution {
public:
bool isPalindrome(string s) {
string onlyS;
for(auto &i : s){
if(('A' <= i && i <= 'Z') || ('0' <= i && i <= '9'))
onlyS.push_back(i);
else if('a' <= i && i <= 'z')
onlyS.push_back(std::toupper(i));
}
if(onlyS.size() < 2)
return true;
for(auto i = 0 ; i < onlyS.size() ; ++i)
if(onlyS[i] != onlyS[onlyS.size() -1 - i])
return false;
return true;
}
};