oj.uz

Submission #649656

# Submission time Handle Problem Language Result Execution time Memory
649656 2022-10-11T07:52:55 Z ToroTN Event Hopping (BOI22_events) C++14
20 / 100
 145 ms 16060 KB 
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define X first
#define Y second
pair<int,int> seg[400005];
int n,t,s[100005],e[100005],l,r,x,y,idx[100005],it,p[100005][25],num,ex[100005],ans;
vector<tuple<int,int,int> > v;
void build(int tree,int st,int ed)
{
    int md=(st+ed)/2;
    if(st==ed)
    {
        seg[tree]={get<1>(v[st]),st};
        return;
    }
    build(2*tree,st,md);
    build(2*tree+1,md+1,ed);
    seg[tree]=max(seg[2*tree],seg[2*tree+1]);
}
pair<int,int> query(int tree,int st,int ed,int l,int r)
{
    int md=(st+ed)/2;
    if(st>r||ed<l)
    {
        return {(int)-2e9,(int)-2e9};
    }
    if(st>=l&&ed<=r)return seg[tree];
    return max(query(2*tree,st,md,l,r),query(2*tree+1,md+1,ed,l,r));
}
int main()
{
    scanf("%d%d",&n,&t);
    for(int i=1;i<=n;i++)
    {
        scanf("%d%d",&s[i],&e[i]);
        v.pb({-e[i],-s[i],i});
    }
    v.pb({-2e9,-2e9,-2e9});
    sort(v.begin(),v.end());
    for(int i=1;i<=n;i++)
    {
        idx[get<2>(v[i])]=i;
        l=get<0>(v[i]);
        r=get<1>(v[i]);
        //printf("%d %d %d\n",l,r,i);
    }
    build(1,1,n);
    for(int i=1;i<=n;i++)
    {
        it=lower_bound(v.begin(),v.end(),make_tuple(get<1>(v[i])+1,-2e9,-2e9))-v.begin()-1;
        num=query(1,1,n,i,it).Y;
        ex[i]=it;
        //printf("%d %d\n",it,num);
        p[i][0]=num;
    }
    for(int i=1;i<=20;i++)
    {
        for(int j=1;j<=n;j++)
        {
            p[j][i]=p[p[j][i-1]][i-1];
        }
    }
    while(t--)
    {
        scanf("%d%d",&x,&y);
        if(e[x]>e[y])
        {
            printf("impossible\n");
            continue;
        }
        x=idx[x];
        y=idx[y];
        ans=0;
        for(int i=20;i>=0;i--)
        {
            if(p[y][i]<x)
            {
                y=p[y][i];
                ans+=(1<<i);
            }
        }
        if(x==y)
        {
            printf("0\n");
            continue;
        }
        if(x<=ex[y])
        {
            printf("%d\n",ans+1);
        }else
        {
            printf("impossible\n");
        }
    }
}

Compilation message

events.cpp: In function 'int main()':
events.cpp:33:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 |     scanf("%d%d",&n,&t);
      |     ~~~~~^~~~~~~~~~~~~~
events.cpp:36:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |         scanf("%d%d",&s[i],&e[i]);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~
events.cpp:66:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   66 |         scanf("%d%d",&x,&y);
      |         ~~~~~^~~~~~~~~~~~~~

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 111 ms 15500 KB Output is correct
3 Correct 99 ms 15576 KB Output is correct
4 Correct 112 ms 15472 KB Output is correct
5 Correct 128 ms 15576 KB Output is correct
6 Correct 113 ms 15648 KB Output is correct
7 Correct 109 ms 15636 KB Output is correct
8 Incorrect 110 ms 16060 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 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 Incorrect 2 ms 468 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 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 Incorrect 2 ms 468 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 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 Incorrect 2 ms 468 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 102 ms 15516 KB Output is correct
2 Correct 104 ms 15616 KB Output is correct
3 Correct 118 ms 15576 KB Output is correct
4 Correct 105 ms 16056 KB Output is correct
5 Correct 128 ms 15840 KB Output is correct
6 Correct 132 ms 15728 KB Output is correct
7 Correct 145 ms 15648 KB Output is correct
8 Correct 121 ms 15812 KB Output is correct
9 Correct 60 ms 14908 KB Output is correct
10 Correct 108 ms 15320 KB Output is correct
11 Correct 110 ms 15080 KB Output is correct
12 Correct 108 ms 15280 KB Output is correct

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 111 ms 15500 KB Output is correct
3 Correct 99 ms 15576 KB Output is correct
4 Correct 112 ms 15472 KB Output is correct
5 Correct 128 ms 15576 KB Output is correct
6 Correct 113 ms 15648 KB Output is correct
7 Correct 109 ms 15636 KB Output is correct
8 Incorrect 110 ms 16060 KB Output isn't correct
9 Halted 0 ms 0 KB -