Kattis

Peragrams

Per recently learned about palindromes. Now he wants to tell us about it and also has more awesome scientific news to share with us.

“A palindrome is a word that is the same no matter whether you read it backward or forward”, Per recently said in an interview. He continued: “For example, add is not a palindrome, because reading it backwards gives dda and it’s actually not the same thing, you see. However, if we reorder the letters of the word, we can actually get a palindrome. Hence, we say that add is a Peragram, because it is an anagram of a palindrome”.

Per gives us a more formal definition of Peragrams: “Like I said, if a word is an anagram of at least one palindrome, we call it a Peragram. And recall that an anagram of a word $w$

Task

Given a string, find the minimum number of letters you have to remove from it, so that the string becomes a Peragram.

Input

Input consists of a string on a single line. The string will contain at least $1$

Output

Output should consist of a single integer on a single line, the minimum number of characters that have to be removed from the string to make it a Peragram.

Sample Input 1	Sample Output 1
abc	2

Sample Input 2	Sample Output 2
aab	0

题意

问给出的字符串需要删除多少个字母后才能组成回文串

思路

相同字母个数是偶数的话才能构成回文，奇数字母只能有一个，所以只需要统计每个字母的个数，然后，答案就是个数为奇数的字母数-1

代码

#include<bits/stdc++.h>
int vis[30];
char aa[1005];
int main() {
    while (~scanf("%s", aa))
    {
        memset(vis, 0, sizeof(vis));
        int len = strlen(aa);
        for (int i = 0; i < len; i++)
        {
            vis[aa[i] - 'a']++;
        }
        int ans = 0;
        for (int i = 0; i < 26; i++)
        {
            if (vis[i] % 2)
            {
                ans++;
            }
        }
        if (ans) ans--;
        printf("%d
", ans);

    }
    return 0;
}