CF Gym 100500D T-shirts

#include<cstdio>
#include<map>
#include<algorithm>

using namespace std;
typedef long long ll;
#define fi first
#define se second
const int maxn = 1e5+5;
map<int,int> S;

int main()
{
    int T;
    scanf("%d",&T);
    for(int k = 1; k <= T; k++){
        int N,D,C;
        scanf("%d%d%d",&N,&D,&C);

        printf("Case %d: ",k);
        if(D<=C) {
            int nn = N;
            while(nn--) { int t; scanf("%d",&t); }
            printf("%lld\n",(ll)D*N);
            continue;
        }
        S.clear();
        for(int i = 0; i < N; i++){
            int t;
            scanf("%d",&t);
            S[t]++;
        }
        int sum = 0;
        ll min_cos = (ll)D*N;
        for(map<int,int>::iterator it = S.begin(); it != S.end(); it++) {
            sum += it->se;
            min_cos = min(((ll)C*it->fi-D)*sum+(ll)D*N,min_cos);
        }
        printf("%lld\n",min_cos);
    }
    return 0;
}