[luoguP2564][SCOI2009]生日礼物（队列）

传送门

当然可以用队列来搞啦。

 # include <iostream>
 # include <cstdio>
 # include <cstring>
 # include <string>
 # include <cmath>
 # include <vector>
 # include <map>
 # include <queue>
 # include <cstdlib>
 # include <algorithm>
 # define MAXN
 using namespace std;

 inline int get_num() {
     int k = , f = ;
     char c = getchar();
     for(; !isdigit(c); c = getchar()) if(c == '-') f = -;
     for(; isdigit(c); c = getchar()) k = k *  + c - '';
     return k * f;
 }

 int n, k, tot, sum, h, t, ans =  << ;
 int num[MAXN];

 struct node
 {
     int a, pos;
 }p[MAXN];

 inline bool cmp(node x, node y)
 {
     return x.pos < y.pos;
 }

 int main()
 {
     int i, j, m;
     n = get_num();
     k = get_num();
     for(i = ; i <= k; i++)
         for(j = , m = get_num(); j <= m; j++)
             p[++tot].a = i, p[tot].pos = get_num();
     sort(p + , p + n + , cmp);
     for(h = , t = ; h <= n; h++)
     {
         while(sum < k && t < n)
         {
             if(!num[p[++t].a]) sum++;
             num[p[t].a]++;
         }
         if(sum == k) ans = min(ans, p[t].pos - p[h].pos);
         num[p[h].a]--;
         if(!num[p[h].a]) sum--;
     }
     printf("%d", ans);
     return ;
 }