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Submission #599495

# Submission time Handle Problem Language Result Execution time Memory
599495 2022-07-19T14:38:38 Z alexander707070 Event Hopping (BOI22_events) C++14
10 / 100
 1500 ms 136964 KB 
#include<bits/stdc++.h>
#define MAXN 400007
using namespace std;

struct event{
    long long s;
    long long e;
    int id;

    inline friend bool operator < (event fr,event sc){
        if(fr.e!=sc.e)return fr.e<sc.e;
        return fr.s<=sc.s;
    }
};

int n,cnt,q,S,E,ans;
int st[MAXN],et[MAXN];
int parent[MAXN];
event e[MAXN];
vector<int> w;
map<int,int> mp;

pair<int,int> mins[8*MAXN];

pair<int,int> best(pair<int,int> fr,pair<int,int> sc){
    if(fr.second<=sc.second)return fr;
    return sc;
}

void update(int v,int l,int r,int pos,int val,int id){
    if(l==r){
        if(val<mins[v].second or val==10000000){
            mins[v]={id,val};
        }
    }else{
        int tt=(l+r)/2;
        if(pos<=tt)update(2*v,l,tt,pos,val,id);
        else update(2*v+1,tt+1,r,pos,val,id);
        mins[v]=best(mins[2*v],mins[2*v+1]);
    }
}

pair<int,int> getmin(int v,int l,int r,int ll,int rr){
    if(ll>rr)return {0,100000000};
    if(l==ll and r==rr){
        return mins[v];
    }else{
        int tt=(l+r)/2;
        return best( getmin(2*v,l,tt,ll,min(tt,rr)) , getmin(2*v+1,tt+1,r,max(tt+1,ll),rr) );
    }
}

int dp[MAXN][20];

void calc(){
    for(int f=0;f<20;f++){
        for(int i=1;i<=n;i++){
            if(f==0)dp[i][f]=parent[i];
            else dp[i][f]=dp[dp[i][f-1]][f-1];
        }
    }
}

int bin(int id,int id2){

    if(id==id2)return 0;
    if(et[id]<st[id2])return -1;
    if(et[id2]>et[id])return -1;
    if(et[id2]>=st[id])return 1;

    int res=0;
    for(int i=19;i>=0;i--){
        if(dp[id][i]!=0 and st[dp[id][i]]>et[id2]){
            id=dp[id][i];
            res+=(1<<i);
        }
    }

    if(parent[id]==0)return -1;
    if(parent[id]==id2)return res+1;
    return res+2;
}

int main(){

    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    cin>>n>>q;
    for(int i=1;i<=n;i++){
        cin>>st[i]>>et[i];
        e[i]={st[i],et[i],i};
        w.push_back(e[i].s);
        w.push_back(e[i].e);
    }

    sort(w.begin(),w.end());
    for(int i=0;i<w.size();i++){
        if(i>0 and w[i]!=w[i-1])cnt++;
        mp[w[i]]=cnt;
    }

    for(int i=1;i<=n;i++){
        e[i].s=mp[e[i].s];
        e[i].e=mp[e[i].e];
    }

    for(int i=0;i<=cnt;i++){
        //update(1,0,cnt,i,10000000,0);
        mins[i]={0,10000000};
    }

    sort(e+1,e+n+1);
    for(int i=1;i<=n;i++){
        pair<int,int> sol={0,100000000};
        for(int f=e[i].s;f<=e[i].e;f++){
            sol=best(sol,mins[f]);
        }
        //parent[e[i].id]=getmin(1,0,cnt,e[i].s,e[i].e).first;
        parent[e[i].id]=sol.first;
        //update(1,0,cnt,e[i].e,e[i].s,e[i].id);
        mins[e[i].e]=best(mins[e[i].e],{e[i].id,e[i].s});
    }
    calc();

    for(long long i=1;i<=100000000000;i++){
        S=E-1; E=S+1;   
    }

    for(int i=1;i<=q;i++){
        cin>>S>>E;
        ans=bin(E,S);
        if(ans==-1)cout<<"impossible\n";
        else cout<<ans<<"\n";
    }


    return 0;
}

Compilation message

events.cpp: In function 'int main()':
events.cpp:99:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   99 |     for(int i=0;i<w.size();i++){
      |                 ~^~~~~~~~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 153 ms 18476 KB Output is correct
3 Correct 155 ms 18504 KB Output is correct
4 Correct 188 ms 18552 KB Output is correct
5 Correct 193 ms 19108 KB Output is correct
6 Correct 164 ms 19596 KB Output is correct
7 Correct 172 ms 19856 KB Output is correct
8 Correct 191 ms 24520 KB Output is correct
9 Correct 167 ms 24504 KB Output is correct
10 Correct 181 ms 18896 KB Output is correct
11 Correct 175 ms 21116 KB Output is correct
12 Correct 92 ms 19016 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 1 ms 468 KB Output is correct
4 Correct 1 ms 468 KB Output is correct
5 Correct 1 ms 468 KB Output is correct
6 Correct 1 ms 468 KB Output is correct
7 Correct 2 ms 468 KB Output is correct
8 Correct 2 ms 596 KB Output is correct
9 Runtime error 170 ms 136964 KB Execution killed with signal 11
10 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 1 ms 468 KB Output is correct
4 Correct 1 ms 468 KB Output is correct
5 Correct 1 ms 468 KB Output is correct
6 Correct 1 ms 468 KB Output is correct
7 Correct 2 ms 468 KB Output is correct
8 Correct 2 ms 596 KB Output is correct
9 Runtime error 170 ms 136964 KB Execution killed with signal 11
10 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 1 ms 468 KB Output is correct
4 Correct 1 ms 468 KB Output is correct
5 Correct 1 ms 468 KB Output is correct
6 Correct 1 ms 468 KB Output is correct
7 Correct 2 ms 468 KB Output is correct
8 Correct 2 ms 596 KB Output is correct
9 Runtime error 170 ms 136964 KB Execution killed with signal 11
10 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 165 ms 18508 KB Output is correct
2 Correct 190 ms 18500 KB Output is correct
3 Correct 192 ms 18484 KB Output is correct
4 Correct 170 ms 24540 KB Output is correct
5 Correct 239 ms 18836 KB Output is correct
6 Correct 275 ms 24168 KB Output is correct
7 Correct 246 ms 24168 KB Output is correct
8 Correct 269 ms 24280 KB Output is correct
9 Execution timed out 1572 ms 15592 KB Time limit exceeded
10 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 153 ms 18476 KB Output is correct
3 Correct 155 ms 18504 KB Output is correct
4 Correct 188 ms 18552 KB Output is correct
5 Correct 193 ms 19108 KB Output is correct
6 Correct 164 ms 19596 KB Output is correct
7 Correct 172 ms 19856 KB Output is correct
8 Correct 191 ms 24520 KB Output is correct
9 Correct 167 ms 24504 KB Output is correct
10 Correct 181 ms 18896 KB Output is correct
11 Correct 175 ms 21116 KB Output is correct
12 Correct 92 ms 19016 KB Output is correct
13 Correct 0 ms 340 KB Output is correct
14 Correct 0 ms 340 KB Output is correct
15 Correct 1 ms 468 KB Output is correct
16 Correct 1 ms 468 KB Output is correct
17 Correct 1 ms 468 KB Output is correct
18 Correct 1 ms 468 KB Output is correct
19 Correct 2 ms 468 KB Output is correct
20 Correct 2 ms 596 KB Output is correct
21 Runtime error 170 ms 136964 KB Execution killed with signal 11
22 Halted 0 ms 0 KB -