Ice cream samples Gym

题目：题目链接

思路：比赛中读错了题，题目要求选一个连续区间，却读成了随便选取几个柜台，英语要好好学啊，读懂题就很简单了，扫一遍就出结果了

AC代码：

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <algorithm>
#include <cstring>
#include <vector>
#include <string>
#include <queue>
#include <map>
#include <set>

#define FRER() freopen("in.txt", "r", stdin);
#define INF 0x3f3f3f3f

using namespace std;

const int maxn = 1000000 + 5;

vector<int> stand[maxn << 1];

int brand[maxn], N, K;

void init() {
    for(int i = 0; i < (N << 1); ++i) 
        stand[i].clear();
    memset(brand, 0, sizeof(brand));
}

int solve() {
    int st = 0, ed = 0, ans = INF, k = 0, now = 0;
    while(ed < (N << 1)) {
        for(int i = 0; i < stand[ed].size(); ++i) {
            ++now;
            if(brand[stand[ed][i]] == 0)
                ++k;
            ++brand[stand[ed][i]];
        }
        ++ed;
        while(k == K && st < ed) {
            ans = min(ans, now);
            for(int i = 0; i < stand[st].size(); ++i) {
                --now;
                --brand[stand[st][i]];
                if(brand[stand[st][i]] == 0)
                    --k;
            }
            ++st;
        }
    }
    return ans == INF ? -1 : ans;
}

int main()
{
    //FRER()
    while(~scanf("%d %d", &N, &K)) {
        init();
        int n, num;
        for(int i = 0; i < N; ++i) {
            scanf("%d", &n);
            for(int j = 0; j < n; ++j) {
                scanf("%d", &num);
                stand[i].push_back(num);
                stand[i + N].push_back(num);
            }
        }
        printf("%d
", solve());
    }
    return 0;
}