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Submission #254600

# Submission time Handle Problem Language Result Execution time Memory
254600 2020-07-30T10:14:13 Z MKopchev Dancing Elephants (IOI11_elephants) C++14
100 / 100
 7532 ms 23964 KB 
#include "elephants.h"
#include <bits/stdc++.h>
using namespace std;

const int nmax=1.5e5+42;

int n,l,where[nmax];

set< pair<int/*position*/,int/*id*/> > active;

int BLOCK;

int which_block[nmax];

int IN=0;

vector< pair<int/*position*/,int/*id*/> > BLOCKS[nmax];

pair<int/*photos*/,int/*last from the same block*/> nxt[nmax];

pair<int/*position*/,int/*id*/> help[nmax];

int get_nxt(int who)
{
    /*
    cout<<"who= "<<who<<endl;
    cout<<"where: ";for(int i=0;i<n;i++)cout<<where[i]<<" ";cout<<endl;
    cout<<"active: ";for(auto k:active)cout<<k.first<<" "<<k.second<<"\t";cout<<endl;
    cout<<"nxt: ";for(int i=0;i<n;i++)cout<<nxt[i].first<<" "<<nxt[i].second<<"\t";cout<<endl;
    cout<<"BLOCKS: "<<endl;
    for(int i=0;i<(n-1)/BLOCK+1;i++)
    {
        cout<<i<<" -> ";for(auto k:BLOCKS[i])cout<<k.first<<" "<<k.second<<"\t";cout<<endl;
    }
    */
    int t=l+where[who];

    t++;

    set< pair<int/*position*/,int/*id*/> >::iterator it=active.lower_bound({t,0});

    if(it==active.end())return -1;

    return (*it).second;
}

void build_block(int which)
{
    //the last might be wrong

    int pointer=BLOCKS[which].size();

    if(pointer==0)return;

    pointer=pointer-2;

    while(pointer>=0&&BLOCKS[which][pointer].first>BLOCKS[which][pointer+1].first)
    {
        swap(BLOCKS[which][pointer],BLOCKS[which][pointer+1]);
        pointer--;
    }

    pointer=BLOCKS[which].size()-1;

    for(int i=BLOCKS[which].size()-1;i>=0;i--)
    {
        if(BLOCKS[which][i].first+l>=BLOCKS[which][BLOCKS[which].size()-1].first)nxt[BLOCKS[which][i].second]={0,BLOCKS[which][i].second};
        else
        {
            while(BLOCKS[which][i].first+l<BLOCKS[which][pointer-1].first)pointer--;

            int moved=BLOCKS[which][pointer].second;

            nxt[BLOCKS[which][i].second]={nxt[moved].first+1,nxt[moved].second};
        }
    }
    /*
    cout<<"building "<<which<<endl;
    for(auto k:BLOCKS[which])cout<<k.first<<" "<<k.second<<"\t";cout<<endl;
    for(int i=0;i<given.size();i++)cout<<nxt[given[i].second].first<<" "<<nxt[given[i].second].second<<"\t";cout<<endl;
    system("pause");
    */
}

void build()
{
    for(int i=0;i<n;i++)
        help[i]={where[i],i};

    sort(help,help+n);

    int total=(n-1)/BLOCK+1;

    for(int i=0;i<total;i++)BLOCKS[i]={};

    for(int i=0;i<n;i++)
    {
        BLOCKS[i/BLOCK].push_back({help[i].first,help[i].second});
        which_block[help[i].second]=i/BLOCK;
    }

    for(int i=0;i<total;i++)
    {
        sort(BLOCKS[i].begin(),BLOCKS[i].end());
        build_block(i);
    }
}

void init(int N,int L,int X[])
{
    n=N;
    l=L;
    for(int i=0;i<N;i++)
    {
        where[i]=X[i];
        active.insert({where[i],i});
    }

    BLOCK=sqrt(n*log(n))+1;
    build();
}


int update(int id,int val)
{
    //cout<<"UPDATE "<<id<<" "<<val<<endl;

    if(n==1)return 1;

    active.erase({where[id],id});

    for(int i=0;true;i++)
        if(BLOCKS[which_block[id]][i]==make_pair(where[id],id))
        {
            BLOCKS[which_block[id]].erase(BLOCKS[which_block[id]].begin()+i);
            break;
        }

    build_block(which_block[id]);

    where[id]=val;

    set< pair<int/*position*/,int/*id*/> >::iterator it=active.lower_bound({where[id],id});
    if(it==active.end())it--;

    int new_block=which_block[(*it).second];

    which_block[id]=new_block;

    active.insert({where[id],id});
    BLOCKS[which_block[id]].push_back({where[id],id});

    build_block(which_block[id]);

    if(BLOCKS[which_block[id]].size()>2*BLOCK)build();

    int ret=0,who=(*active.begin()).second;

    while(who!=-1)
    {
        ret+=nxt[who].first;

        who=nxt[who].second;

        ret++;

        who=get_nxt(who);
    }

    return ret;
}

/*
int N_,L_,X_[nmax];
int main()
{
    cin>>N_>>L_;
    for(int i=0;i<N_;i++)cin>>X_[i];

    init(N_,L_,X_);

    int q;
    cin>>q;

    for(int i=1;i<=q;i++)
    {
        int pos,val;
        cin>>pos>>val;

        cout<<update(pos,val)<<endl;
    }


    cout<<update(0,10)<<endl;

    cout<<update(5,11)<<endl;

    cout<<update(7,12)<<endl;

    cout<<update(8,13)<<endl;

    cout<<update(4,14)<<endl;

    cout<<update(6,15)<<endl;
    return 0;
}
*/

Compilation message

elephants.cpp: In function 'int update(int, int)':
elephants.cpp:155:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if(BLOCKS[which_block[id]].size()>2*BLOCK)build();
        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 3840 KB Output is correct
2 Correct 2 ms 3840 KB Output is correct
3 Correct 3 ms 3840 KB Output is correct

Subtask #2
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 3840 KB Output is correct
2 Correct 2 ms 3840 KB Output is correct
3 Correct 3 ms 3840 KB Output is correct
4 Correct 2 ms 3968 KB Output is correct
5 Correct 3 ms 3968 KB Output is correct
6 Correct 3 ms 3840 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 3840 KB Output is correct
2 Correct 2 ms 3840 KB Output is correct
3 Correct 3 ms 3840 KB Output is correct
4 Correct 2 ms 3968 KB Output is correct
5 Correct 3 ms 3968 KB Output is correct
6 Correct 3 ms 3840 KB Output is correct
7 Correct 362 ms 5752 KB Output is correct
8 Correct 452 ms 6136 KB Output is correct
9 Correct 689 ms 8824 KB Output is correct
10 Correct 782 ms 8824 KB Output is correct
11 Correct 903 ms 8812 KB Output is correct
12 Correct 1027 ms 9080 KB Output is correct
13 Correct 1117 ms 8824 KB Output is correct

Subtask #4
47.0 / 47.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 3840 KB Output is correct
2 Correct 2 ms 3840 KB Output is correct
3 Correct 3 ms 3840 KB Output is correct
4 Correct 2 ms 3968 KB Output is correct
5 Correct 3 ms 3968 KB Output is correct
6 Correct 3 ms 3840 KB Output is correct
7 Correct 362 ms 5752 KB Output is correct
8 Correct 452 ms 6136 KB Output is correct
9 Correct 689 ms 8824 KB Output is correct
10 Correct 782 ms 8824 KB Output is correct
11 Correct 903 ms 8812 KB Output is correct
12 Correct 1027 ms 9080 KB Output is correct
13 Correct 1117 ms 8824 KB Output is correct
14 Correct 570 ms 6392 KB Output is correct
15 Correct 622 ms 6696 KB Output is correct
16 Correct 1552 ms 9024 KB Output is correct
17 Correct 1864 ms 10796 KB Output is correct
18 Correct 2041 ms 10784 KB Output is correct
19 Correct 1960 ms 10628 KB Output is correct
20 Correct 1839 ms 10872 KB Output is correct
21 Correct 1811 ms 10892 KB Output is correct
22 Correct 1747 ms 10576 KB Output is correct

Subtask #5
3.0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 3840 KB Output is correct
2 Correct 2 ms 3840 KB Output is correct
3 Correct 3 ms 3840 KB Output is correct
4 Correct 2 ms 3968 KB Output is correct
5 Correct 3 ms 3968 KB Output is correct
6 Correct 3 ms 3840 KB Output is correct
7 Correct 362 ms 5752 KB Output is correct
8 Correct 452 ms 6136 KB Output is correct
9 Correct 689 ms 8824 KB Output is correct
10 Correct 782 ms 8824 KB Output is correct
11 Correct 903 ms 8812 KB Output is correct
12 Correct 1027 ms 9080 KB Output is correct
13 Correct 1117 ms 8824 KB Output is correct
14 Correct 570 ms 6392 KB Output is correct
15 Correct 622 ms 6696 KB Output is correct
16 Correct 1552 ms 9024 KB Output is correct
17 Correct 1864 ms 10796 KB Output is correct
18 Correct 2041 ms 10784 KB Output is correct
19 Correct 1960 ms 10628 KB Output is correct
20 Correct 1839 ms 10872 KB Output is correct
21 Correct 1811 ms 10892 KB Output is correct
22 Correct 1747 ms 10576 KB Output is correct
23 Correct 5180 ms 18628 KB Output is correct
24 Correct 5600 ms 18624 KB Output is correct
25 Correct 4372 ms 18620 KB Output is correct
26 Correct 4806 ms 18700 KB Output is correct
27 Correct 6559 ms 18652 KB Output is correct
28 Correct 830 ms 9056 KB Output is correct
29 Correct 835 ms 9036 KB Output is correct
30 Correct 840 ms 9080 KB Output is correct
31 Correct 821 ms 9080 KB Output is correct
32 Correct 5449 ms 23144 KB Output is correct
33 Correct 3210 ms 22460 KB Output is correct
34 Correct 4241 ms 23336 KB Output is correct
35 Correct 3120 ms 23672 KB Output is correct
36 Correct 2005 ms 23164 KB Output is correct
37 Correct 5745 ms 23964 KB Output is correct
38 Correct 5910 ms 22344 KB Output is correct
39 Correct 6868 ms 23416 KB Output is correct
40 Correct 6054 ms 22392 KB Output is correct
41 Correct 7467 ms 23352 KB Output is correct
42 Correct 7532 ms 23584 KB Output is correct