Given a string which consists of lowercase or uppercase letters, find the length of the longest palindromes that can be built with those letters.
This is case sensitive, for example "Aa" is not considered a palindrome here.
Note:
Assume the length of given string will not exceed 1,010.
Example:
Input: "abccccdd" Output: 7 Explanation: One longest palindrome that can be built is "dccaccd", whose length is 7.
class Solution {
public:
int longestPalindrome(string s) {
unordered_map<char, int> mp;
int nums = 0;
bool flag = false;
for (int i = 0; i < s.length(); ++i)
mp[s[i]]++;
for (auto it = mp.begin(); it != mp.end(); ++it) {
nums += it->second/2 * 2;
if (it->second % 2 != 0 && !flag)
flag = true;
}
if (flag) nums++;
return nums;
}
private:
static bool cmp(int a, int b) {
return a >= b;
}
};
Approach #2: Java.
class Solution {
public int longestPalindrome(String s) {
int[] count = new int[128];
for (char c : s.toCharArray())
count[c]++;
int ans = 0;
for (int v : count) {
ans += v / 2 * 2;
if (ans % 2 == 0 && v % 2 == 1)
ans++;
}
return ans;
}
}
Approach #3: Python.
class Solution(object):
def longestPalindrome(self, s):
"""
:type s: str
:rtype: int
"""
ans = 0
for v in collections.Counter(s).itervalues():
ans += v / 2 * 2
if ans % 2 == 0 and v % 2 == 1:
ans += 1
return ans
| Time Submitted | Status | Runtime | Language |
|---|---|---|---|
| a few seconds ago | Accepted | 44 ms | python |
| 2 minutes ago | Accepted | 5 ms | java |
| 5 minutes ago | Accepted | 8 ms | cpp |
原文：https://www.cnblogs.com/ruruozhenhao/p/9969751.html