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답안 #599461

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
599461 2022-07-19T14:19:33 Z alexander707070 Event Hopping (BOI22_events) C++11
30 / 100
 372 ms 140148 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 pos[MAXN],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);
    }

    sort(e+1,e+n+1);
    for(int i=1;i<=n;i++){
        parent[e[i].id]=getmin(1,0,cnt,e[i].s,e[i].e).first;
        update(1,0,cnt,e[i].e,e[i].s,e[i].id);
    }
    calc();

    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

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 201 ms 19736 KB Output is correct
3 Correct 249 ms 19836 KB Output is correct
4 Correct 372 ms 19780 KB Output is correct
5 Correct 225 ms 20248 KB Output is correct
6 Correct 274 ms 20740 KB Output is correct
7 Correct 195 ms 21000 KB Output is correct
8 Correct 240 ms 27000 KB Output is correct
9 Correct 234 ms 27032 KB Output is correct
10 Correct 192 ms 20204 KB Output is correct
11 Correct 217 ms 24204 KB Output is correct
12 Correct 138 ms 20340 KB Output is correct

Subtask #2
0 / 10.0

# 결과 실행 시간 메모리 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 596 KB Output is correct
8 Correct 2 ms 596 KB Output is correct
9 Runtime error 161 ms 140148 KB Execution killed with signal 11
10 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# 결과 실행 시간 메모리 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 596 KB Output is correct
8 Correct 2 ms 596 KB Output is correct
9 Runtime error 161 ms 140148 KB Execution killed with signal 11
10 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# 결과 실행 시간 메모리 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 596 KB Output is correct
8 Correct 2 ms 596 KB Output is correct
9 Runtime error 161 ms 140148 KB Execution killed with signal 11
10 Halted 0 ms 0 KB -

Subtask #5
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 191 ms 19840 KB Output is correct
2 Correct 231 ms 19768 KB Output is correct
3 Correct 251 ms 19736 KB Output is correct
4 Correct 240 ms 27140 KB Output is correct
5 Correct 193 ms 20124 KB Output is correct
6 Correct 284 ms 26736 KB Output is correct
7 Correct 305 ms 26800 KB Output is correct
8 Correct 310 ms 26840 KB Output is correct
9 Correct 227 ms 25972 KB Output is correct
10 Correct 272 ms 26380 KB Output is correct
11 Correct 324 ms 26164 KB Output is correct
12 Correct 271 ms 26400 KB Output is correct

Subtask #6
0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 201 ms 19736 KB Output is correct
3 Correct 249 ms 19836 KB Output is correct
4 Correct 372 ms 19780 KB Output is correct
5 Correct 225 ms 20248 KB Output is correct
6 Correct 274 ms 20740 KB Output is correct
7 Correct 195 ms 21000 KB Output is correct
8 Correct 240 ms 27000 KB Output is correct
9 Correct 234 ms 27032 KB Output is correct
10 Correct 192 ms 20204 KB Output is correct
11 Correct 217 ms 24204 KB Output is correct
12 Correct 138 ms 20340 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 596 KB Output is correct
20 Correct 2 ms 596 KB Output is correct
21 Runtime error 161 ms 140148 KB Execution killed with signal 11
22 Halted 0 ms 0 KB -