BZOJ-1293: [SCOI2009]生日礼物 (单调队列)

 1 #include "bits/stdc++.h"
 2 using namespace std;
 3 typedef long long LL;
 4 const int MAX=1e6+5;
 5 int n,K,ans,now,cnt,a[MAX];
 6 struct Node{
 7     int x,y;
 8     bool operator < (const Node &tt) const { return x<tt.x; }
 9 }cad[MAX];
10 inline int read(){
11     int an=0,x=1;char c=getchar();
12     while (c<‘0‘ || c>‘9‘) {if (c==‘-‘) x=-1;c=getchar();}
13     while (c>=‘0‘ && c<=‘9‘) {an=(an<<3)+(an<<1)+c-‘0‘;c=getchar();}
14     return an*x;
15 }
16 void add(int x){if (!a[cad[x].y]) now++;a[cad[x].y]++;}
17 void del(int x){a[cad[x].y]--;if (!a[cad[x].y]) now--;}
18 int main(){
19     freopen ("present.in","r",stdin);freopen ("present.out","w",stdout);
20     int i,j,zt;
21     n=read();K=read();
22     for (i=1;i<=K;i++){
23         zt=read();
24         for (j=1;j<=zt;j++)
25             cad[++cnt].x=read(),cad[cnt].y=i;
26     }
27     sort(cad+1,cad+cnt+1);
28     add(1);int L=1,R=1;ans=1e9;
29     while (L<n){
30         while (now<K && R<n) add(++R);
31         if (now>=K) ans=min(ans,cad[R].x-cad[L].x);
32         del(L),++L;
33     }
34     printf("%d",ans);
35     return 0;
36 }