Submission #954500

#	Time	Username	Problem	Language	Result	Execution time	Memory
954500		boyliguanhan	Žarulje (COI15_zarulje)	C++17	100 / 100	344 ms	203192 KiB

zarulje

#include<bits/stdc++.h>
#include<bits/extc++.h>
using namespace __gnu_pbds;
using namespace std;
#define int long long
#pragma GCC optimize(2)

const int M=1e9+7,N=1<<18;
#define L l.top()
#define R r.top()
int H[N],fac[N],inv[N],res[N];
stack<int>KILL[N],l,r;
gp_hash_table<int,int>mp1,mp2;
int pw(int x,int k=M-2){
    if(!k) return 1;
    int y=pw(x,k/2);
    y=y*y%M;
    if(k&1)y=y*x%M;
    return y;
}
int C(int a,int b){
    return fac[a+b]*inv[b]%M*inv[a]%M;
}
int get(int x){
    return C(mp1[x],mp2[x]);
}
signed main(){
    l.push(0),r.push(0);
    cin.tie(0)->sync_with_stdio(0);
    fac[0]=1;
    for(int i=1;i<N;i++)
        fac[i]=fac[i-1]*i%M;
    inv[N-1]=pw(fac[N-1]);
    res[1]=1;
    for(int i=N;--i;)
        inv[i-1]=inv[i]*i%M;
    int n,k;
    cin>>n>>k;
    for(int i=1;i<=n;i++)
        cin>>H[i];
    for(int i=n;i>1;mp2[H[i]]++,r.push(H[i--]))
        while(R>H[i])
            KILL[i].push(R),mp2[R]--,r.pop();
    for(int i=2;i<=n;i++) {
        res[i]=res[i-1];
        while(L>H[i-1])
            res[i]=res[i]*pw(get(L))%M,mp1[L]--,res[i]=res[i]*get(L)%M,l.pop();
        res[i]=res[i]*pw(get(R))%M,mp2[R]--,res[i]=res[i]*get(R)%M,r.pop();
        l.push(H[i-1]),res[i]=res[i]*pw(get(L))%M,mp1[L]++,res[i]=res[i]*get(L)%M;
        while(KILL[i].size())
            r.push(KILL[i].top()),res[i]=res[i]*pw(get(R))%M,mp2[R]++,res[i]=res[i]*get(R)%M,KILL[i].pop();
    }
    while(k--){
        int x;
        cin>>x;
        cout<<res[x]<<'\n';
    }
}

• Subtask 1: 22 / 22
• Subtask 2: 38 / 38
• Subtask 3: 40 / 40