Appleman and Card Game（贪心）

原题链接

B. Appleman and Card Game

time limit per test1 second

memory limit per test256 megabytes

inputstandard input

outputstandard output

Appleman has n cards. Each card has an uppercase letter written on it. Toastman must choose k cards from Appleman’s cards. Then Appleman should give Toastman some coins depending on the chosen cards. Formally, for each Toastman’s card i you should calculate how much Toastman’s cards have the letter equal to letter on ith, then sum up all these quantities, such a number of coins Appleman should give to Toastman.

Given the description of Appleman’s cards. What is the maximum number of coins Toastman can get?

Input

The first line contains two integers n and k (1 ≤ k ≤ n ≤ 105). The next line contains n uppercase letters without spaces — the i-th letter describes the i-th card of the Appleman.

Output

Print a single integer – the answer to the problem.

Examples

input

15 10

DZFDFZDFDDDDDDF

output

82

input

6 4

YJSNPI

output

4

Note

In the first test example Toastman can choose nine cards with letter D and one additional card with any letter. For each card with D he will get 9 coins and for the additional card he will get 1 coin.

这个题用到了贪心的思想，先对这些信的数量进行排序，当然最大的数量一定是先进行计算的，但是注意这个题会超出int的范围

#include <cstdio>
#include <iostream>
#include <algorithm>
using namespace std;
const int maxn = 100000 +10;
char s[maxn];
typedef unsigned long long ll;
ll a[26];
bool cmp(ll x,ll y){
return x>y;
}
int main(){
ll n,k;//int n,k;这里不用int类型是因为后面k*k的时候会爆掉，或者强制转换，或者就是为了避免问题就之前就把可能会出问题的
while(cin >> n >> k){
cin >> s;
for(int i=0;i<n;i++)
a[s[i]-'A']++;
sort(a,a+26,cmp);
ll sum=0;
for(int i=0;i<26;i++){
if(k>=a[i]){
sum += (a[i] * a[i]);
k -= a[i];
if(k == 0) break;
}
else{
sum += (k*k);//但是这里这一步不太懂//这里的k*k可能就会爆掉
break;
}
}
cout << sum << endl;
}
return 0;
}