All Palindrome

链接：https://ac.nowcoder.com/acm/contest/624/A
来源：牛客网
 

Ramen likes palindrome.

A palindrome is a word, number, phrase, or other sequences of characters which reads the same backward as forward, such as madam or racecar or the number 10801.

An all palindrome is such a string that each substring of it is a palindrome. For example, the string aaa is an all palindrome while aba is not.

There is a string, and Ramen wants to make it an all palindrome string. He has a magic skill that he can remove any character of the string as much as he wants. But cast such a spell will cost him a lot of energy. As a lazy boy, he wants to save energy to play games, so can you tell him the minimum number of the necessary characters that he needs to remove?
 

输入描述:

The input contains precisely two lines.

The first line is an integer n(1 <= n <= 100000), which indicates the length of the given string.

The second line is the given string S. It's guaranteed that S contains only lower case Lattin letters, i.e., a-z.

输出描述:

For each test case, output the minimum number of necessary removals.

示例1

输入

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22
welcometotheupcofhitwh

输出

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19

示例2

输入

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20
itstheeasiestproblem

输出

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16

示例3

输入

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25
goandgrabyoursignupreward

输出

复制

21

思路：炸一眼以为是回文串更改判断之后发现水体直接输出桶排最大的

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
using namespace std;
int book[100009];
int main()
{
    int n;string a;
    scanf("%d",&n);
    cin>>a;int max1 = 0;
    for(int i = 0; i < n;++i)
    {
        book[a[i]-'a']++;
        if(book[a[i]-'a']>max1)
        {
            max1 = book[a[i]-'a'];
        }
    }
     
    printf("%d\n",n-max1);
    return 0;
}