CodeForces - 958 F2 Lightsabers (medium) . (尺取法）

#include <iostream>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <map>
#include <queue>
#include <vector>
#include <cstring>
#include <iomanip>
#include <set>
#include<ctime>
//CLOCKS_PER_SEC
#define se second
#define fi first
#define ll long long
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
#define Pii pair<int,int>
#define Pli pair<ll,int>
#define ull unsigned long long
#define pb push_back
#define fio ios::sync_with_stdio(false);cin.tie(0)
const double Pi=3.14159265;
const double e=2.71828182;
const int N=3e5+5;
const ull base=163;
const int INF=0x3f3f3f3f;
using namespace std;
int a[N];
int b[N];int main(){
    int n,m;
    fio;
    cin>>n>>m;
    for(int i=1;i<=n;i++){
        cin>>a[i];
    }
    int sum=0;
    int pp=0;
    for(int i=1;i<=m;i++){
        cin>>b[i];
        if(b[i]==0)
        sum++;
        pp+=b[i];
    }
    int c[N];
    int l=1,r=1;
    int MIN=INF;
    int op=0;
    for(;;){
        while(r<=n&&sum<m){
            c[a[r]]++;
            if(c[a[r]]==b[a[r]])sum++;
            r++;
        }
        if(sum<m)break;
        MIN=min(MIN,r-l-pp);
        if(c[a[l]]==b[a[l]])sum--;
        c[a[l]]--;
        l++;
    }
    if(MIN!=INF)
    cout<<MIN<<endl;
    else cout<<-1<<endl;
    return 0;
}