看看有什么问题CF 462B. Appleman and Card Game

#include<iostream>#include<cstring>#include<algorithm>#define MAXN 100000+5#define LL long longusing namespace std;char a[MAXN];bool cmp(int a,int b){return a>b;}int main(){int alpha[26];memset(alpha,0,sizeof(alpha));int n,k;LL sum,num;cin>>n>>k;for(int i=0;i<n;i++){cin>>a[i];alpha[a[i]-'A']++;}sort(alpha,alpha+26,cmp);num=0,sum=0;if(alpha[0]>k){sum=k*k;num=alpha[0];};for(int i=0;num<k;i++){num+=alpha[i];if(num>k) sum+=(LL)(alpha[i]-num+k)*(LL)(alpha[i]-num+k);else {sum+=alpha[i]*alpha[i];}}cout<<sum<<endl;return 0;}