BZOJ 1293 生日礼物(尺取法)

把坐标离散化之后就是很普通的尺取法啦。

# include <cstdio>
# include <cstring>
# include <cstdlib>
# include <iostream>
# include <vector>
# include <queue>
# include <stack>
# include <map>
# include <set>
# include <cmath>
# include <algorithm>
using namespace std;
# define lowbit(x) ((x)&(-x))
# define pi 3.1415926535
# define eps 1e-
# define MOD
# define INF
# define mem(a,b) memset(a,b,sizeof(a))
# define FOR(i,a,n) for(int i=a; i<=n; ++i)
# define FO(i,a,n) for(int i=a; i<n; ++i)
# define bug puts("H");
# define lch p<<,l,mid
# define rch p<<|,mid+,r
# define mp make_pair
# define pb push_back
typedef pair<int,int> PII;
typedef vector<int> VI;
# pragma comment(linker, "/STACK:1024000000,1024000000")
typedef long long LL;
int Scan() {
    int res=, flag=;
    char ch;
    if((ch=getchar())=='-') flag=;
    else if(ch>=''&&ch<='') res=ch-'';
    while((ch=getchar())>=''&&ch<='')  res=res*+(ch-'');
    return flag?-res:res;
}
void Out(int a) {
    if(a<) {putchar('-'); a=-a;}
    if(a>=) Out(a/);
    putchar(a%+'');
}
const int N=;
//Code begin...

struct Node{int c; LL pos;}node[N];
int vis[], num;

bool comp(Node a, Node b){return a.pos<b.pos;}
int main ()
{
    LL ans=(LL)<<;
    int n, k, t;
    n=Scan(); k=Scan();
    FOR(i,,k) {
        t=Scan();
        while (t--) node[++num].pos=Scan(), node[num].c=i;
    }
    sort(node+,node+n+,comp);
    num=;
    int l=, r=;
    while () {
        while (num<k) {
            ++r;
            if (r>n) break;
            if (vis[node[r].c]==) ++num;
            ++vis[node[r].c];
        }
        if (r>n) break;
        ans=min(ans,node[r].pos-node[l].pos);
        --vis[node[l].c];
        if (vis[node[l].c]==) --num;
        ++l;
    }
    printf("%lld\n",ans);
    return ;
}