oj.uz

Submission #1104108

# Submission time Handle Problem Language Result Execution time Memory
1104108 2024-10-22T20:03:47 Z andrewp Event Hopping (BOI22_events) C++14
30 / 100
 147 ms 31932 KB 
//Dedicated to my love, ivaziva
#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std; 
using ll=int64_t;
using pii=pair<int,int>; 
using pll=pair<int,int>;
#define all(x) x.begin(),x.end()
#define raint(x) x.rbegin(),x.rend()
#define pb push_back
#define fi first
#define se second
#define mp make_pair 
#define dbg(x) cerr<<#x<<": "<<x<<'\n';
#define dbga(A,l_,r_){cerr<<#A<<": ";for(int i_=l_;i_<=r_;i_++)cerr<<A[i_]<<' ';cerr<<'\n';}
#define dbgv(a_){cerr<<#a_<<": ";for(auto x_:a_) cerr<<x_<<' ';cerr<<'\n';}
const int N=1e5+50;
int n,q,l[N],r[N],ord[N],id[N],prv[N],lg[N],jmp[N][20];
pii up[N][20];
bool cmp(int i,int j){
    if(r[i]==r[j]) return l[i]<l[j];
    return r[i]<r[j];
}
pii Get(int l,int r){
    int k=lg[r-l+1]; 
    return min(up[l][k],up[r-(1<<k)+1][k]);
}
int main(){ 
    scanf("%d%d",&n,&q); 
    vector<int> cmprs; 
    for(int i=0;i<n;i++){
        scanf("%d%d",&l[i],&r[i]);
        cmprs.pb(l[i]); cmprs.pb(r[i]);
    }
    sort(all(cmprs)); cmprs.erase(unique(all(cmprs)),cmprs.end());
    for(int i=0;i<n;i++){
        l[i]=lower_bound(all(cmprs),l[i])-cmprs.begin();
        r[i]=lower_bound(all(cmprs),r[i])-cmprs.begin();
    }  
    iota(ord,ord+n,0);
    sort(ord,ord+n,cmp); 
    for(int i=0;i<n;i++) id[ord[i]]=i;
    vector<int> swl(n),swr(n);
    for(int i=2;i<=n;i++) lg[i]=lg[i/2]+1; 
    for(int i=0;i<n;i++) swl[i]=l[ord[i]],swr[i]=r[ord[i]];
    for(int i=0;i<n;i++) l[i]=swl[i],r[i]=swr[i]; 
    for(int i=0;i<n;i++) up[i][0]=mp(l[i],i);
    for(int j=1;j<20;j++) for(int i=0;i+(1<<j)<=n;i++){
        up[i][j]=min(up[i][j-1],up[i+(1<<(j-1))][j-1]);
    } 
    for(int i=0;i<n;i++){
        int bot=0,top=i;
        prv[i]=i;
        while(bot<=top){
            int mid=(bot+top)/2;
            if(r[mid]>=l[i]){
                prv[i]=mid;
                top=mid-1;
            }else bot=mid+1;
        }
    }  
    for(int i=0;i<n;i++) jmp[i][0]=prv[i];
    for(int j=1;j<20;j++) for(int i=0;i<n;i++){
        jmp[i][j]=jmp[Get(jmp[i][j-1],i).se][j-1];
    }
    while(q--){
        int s,e; scanf("%d%d",&s,&e);
        --s,--e; s=id[s],e=id[e];
        if(s>e){printf("impossible\n");continue;}
        if(s==e){printf("0\n");continue;}
        if(r[s]>=l[e]&&r[s]<=r[e]){printf("1\n");continue;} 
        int ans=0;
        for(int i=19;i>=0;i--){
            if(jmp[e][i]>s){
                ans+=(1<<i);
                e=Get(jmp[e][i],e).se;
            }
        }
        if(jmp[e][0]<=s) ans++;
        else{printf("impossible\n");continue;}
        printf("%d\n",ans);
    }
    return 0;       
}

Compilation message

events.cpp: In function 'int main()':
events.cpp:29:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 |     scanf("%d%d",&n,&q);
      |     ~~~~~^~~~~~~~~~~~~~
events.cpp:32:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   32 |         scanf("%d%d",&l[i],&r[i]);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~
events.cpp:67:23: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   67 |         int s,e; scanf("%d%d",&s,&e);
      |                  ~~~~~^~~~~~~~~~~~~~

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4432 KB Output is correct
2 Correct 98 ms 31432 KB Output is correct
3 Correct 103 ms 31420 KB Output is correct
4 Correct 111 ms 31420 KB Output is correct
5 Correct 121 ms 31420 KB Output is correct
6 Correct 118 ms 31428 KB Output is correct
7 Correct 119 ms 31624 KB Output is correct
8 Correct 117 ms 31932 KB Output is correct
9 Correct 107 ms 31932 KB Output is correct
10 Correct 117 ms 31676 KB Output is correct
11 Incorrect 114 ms 31932 KB Output isn't correct
12 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4432 KB Output is correct
2 Correct 1 ms 4432 KB Output is correct
3 Correct 2 ms 4688 KB Output is correct
4 Correct 2 ms 4688 KB Output is correct
5 Correct 2 ms 4688 KB Output is correct
6 Correct 2 ms 4688 KB Output is correct
7 Correct 2 ms 4688 KB Output is correct
8 Correct 2 ms 4688 KB Output is correct
9 Correct 2 ms 4688 KB Output is correct

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4432 KB Output is correct
2 Correct 1 ms 4432 KB Output is correct
3 Correct 2 ms 4688 KB Output is correct
4 Correct 2 ms 4688 KB Output is correct
5 Correct 2 ms 4688 KB Output is correct
6 Correct 2 ms 4688 KB Output is correct
7 Correct 2 ms 4688 KB Output is correct
8 Correct 2 ms 4688 KB Output is correct
9 Correct 2 ms 4688 KB Output is correct
10 Correct 1 ms 4432 KB Output is correct
11 Correct 1 ms 4432 KB Output is correct
12 Correct 2 ms 4856 KB Output is correct
13 Correct 2 ms 4688 KB Output is correct
14 Correct 2 ms 4688 KB Output is correct
15 Correct 2 ms 4688 KB Output is correct
16 Correct 2 ms 4596 KB Output is correct
17 Correct 2 ms 4688 KB Output is correct
18 Correct 1 ms 4688 KB Output is correct
19 Correct 29 ms 8304 KB Output is correct
20 Correct 27 ms 8264 KB Output is correct
21 Correct 39 ms 8520 KB Output is correct
22 Incorrect 28 ms 8784 KB Output isn't correct
23 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4432 KB Output is correct
2 Correct 1 ms 4432 KB Output is correct
3 Correct 2 ms 4688 KB Output is correct
4 Correct 2 ms 4688 KB Output is correct
5 Correct 2 ms 4688 KB Output is correct
6 Correct 2 ms 4688 KB Output is correct
7 Correct 2 ms 4688 KB Output is correct
8 Correct 2 ms 4688 KB Output is correct
9 Correct 2 ms 4688 KB Output is correct
10 Correct 1 ms 4432 KB Output is correct
11 Correct 1 ms 4432 KB Output is correct
12 Correct 2 ms 4688 KB Output is correct
13 Correct 2 ms 4688 KB Output is correct
14 Correct 2 ms 4688 KB Output is correct
15 Correct 2 ms 4688 KB Output is correct
16 Correct 2 ms 4688 KB Output is correct
17 Correct 2 ms 4704 KB Output is correct
18 Correct 2 ms 4556 KB Output is correct
19 Correct 78 ms 29696 KB Output is correct
20 Correct 72 ms 28860 KB Output is correct
21 Correct 98 ms 29628 KB Output is correct
22 Incorrect 93 ms 29696 KB Output isn't correct
23 Halted 0 ms 0 KB -

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 104 ms 31420 KB Output is correct
2 Correct 113 ms 31432 KB Output is correct
3 Correct 118 ms 31420 KB Output is correct
4 Correct 109 ms 31932 KB Output is correct
5 Correct 124 ms 31676 KB Output is correct
6 Correct 147 ms 31440 KB Output is correct
7 Correct 115 ms 31424 KB Output is correct
8 Correct 110 ms 31676 KB Output is correct
9 Correct 77 ms 29628 KB Output is correct
10 Correct 105 ms 31172 KB Output is correct
11 Correct 99 ms 30908 KB Output is correct
12 Correct 109 ms 31176 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4432 KB Output is correct
2 Correct 98 ms 31432 KB Output is correct
3 Correct 103 ms 31420 KB Output is correct
4 Correct 111 ms 31420 KB Output is correct
5 Correct 121 ms 31420 KB Output is correct
6 Correct 118 ms 31428 KB Output is correct
7 Correct 119 ms 31624 KB Output is correct
8 Correct 117 ms 31932 KB Output is correct
9 Correct 107 ms 31932 KB Output is correct
10 Correct 117 ms 31676 KB Output is correct
11 Incorrect 114 ms 31932 KB Output isn't correct
12 Halted 0 ms 0 KB -