oj.uz

Submission #879571

# Submission time Handle Problem Language Result Execution time Memory
879571 2023-11-27T16:28:33 Z andrei_boaca Highway Tolls (IOI18_highway) C++17
18 / 100
 745 ms 262144 KB 
#include "highway.h"
#include <bits/stdc++.h>
//#include "grader.cpp"
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
mt19937 rng(chrono::steady_clock().now().time_since_epoch().count());
int n,m,niv[100005],par[100005],topar[100005],dp[21][100005],in[100005],out[100005],timp;
ll dist,AA,BB;
vector<pii> muchii[100005];
vector<pii> g;
vector<int> w;
ll memo[100005],calls;
bool isancestor(int a,int b)
{
    return in[a]<=in[b]&&out[a]>=out[b];
}
int LCA(int a,int b)
{
    if(niv[a]>niv[b])
        swap(a,b);
    if(isancestor(a,b))
        return a;
    for(int i=20;i>=0;i--)
        if(dp[i][a]!=-1&&!isancestor(dp[i][a],b))
            a=dp[i][a];
    return par[a];
}
void dfs(int nod)
{
    timp++;
    in[nod]=timp;
    dp[0][nod]=par[nod];
    for(int i=1;i<=20;i++)
    {
        if(dp[i-1][nod]==-1)
        {
            dp[i][nod]=-1;
            continue;
        }
        dp[i][nod]=dp[i-1][dp[i-1][nod]];
    }
    for(auto i:muchii[nod])
        if(i.first!=par[nod])
        {
            par[i.first]=nod;
            niv[i.first]=niv[nod]+1;
            topar[i.first]=i.second;
            dfs(i.first);
        }
    out[nod]=timp;
}
ll buildniv(int p)
{
    if(memo[p]!=0)
        return memo[p];
    for(int i=0;i<m;i++)
    {
        w[i]=1;
        if(min(niv[g[i].first],niv[g[i].second])<=p)
            w[i]=0;
    }
    calls++;
    assert(calls<=60);
    memo[p]=ask(w);
    return memo[p];
}
int getnode(vector<int> cand)
{
    while(true)
    {
        if(cand.size()==1)
            return cand[0];
        vector<int> x,y;
        int lg=cand.size();
        for(int i=0;i<cand.size();i++)
        {
            if(i<lg/2)
                x.push_back(cand[i]);
            else
                y.push_back(cand[i]);
        }
        for(int i=0;i<m;i++)
            w[i]=1;
        for(int i:x)
            w[topar[i]]=0;
        calls++;
        assert(calls<=60);
        ll val=ask(w);
        if(val<dist*BB)
            cand=x;
        else
            cand=y;
    }
    return -1;
}
void find_pair(int N, std::vector<int> U, std::vector<int> V, int A, int B)
{
    AA=A;
    BB=B;
    n=N;
    m=U.size();
    for(int i=0;i<m;i++)
    {
        int a=U[i],b=V[i];
        g.push_back({a,b});
        muchii[a].push_back({b,i});
        muchii[b].push_back({a,i});
    }
    for(int i=0;i<n;i++)
        par[i]=-1;
    int root=rng()%n;
    niv[root]=1;
    dfs(root);
    int nivmax=0;
    for(int i=0;i<n;i++)
        nivmax=max(nivmax,niv[i]);
    for(int i=0;i<m;i++)
        w.push_back(0);
    calls++;
    assert(calls<=60);
    dist=ask(w)/A;
    int nivlca=nivmax;
    int st=1;
    int dr=nivmax-1;
    while(st<=dr)
    {
        int mij=(st+dr)/2;
        ll val=buildniv(mij);
        if(val<dist*B)
        {
            nivlca=mij;
            dr=mij-1;
        }
        else
            st=mij+1;
    }
    int nivS=nivlca;
    int nivT=0;
    st=nivlca;
    dr=nivmax-1;
    while(st<=dr)
    {
        int mij=(st+dr)/2;
        ll nra=2*(mij-nivlca);
        if(nra<=dist)
        {
            ll val=buildniv(mij);
            ll val2=buildniv(mij-1);
            if(val2==val+2LL*(B-A))
            {
                nivS=mij+1;
                st=mij+1;
                continue;
            }
        }
        dr=mij-1;
    }
    nivT=nivlca+(dist-(nivS-nivlca));
    //assert(nivS<=nivT);
    vector<int> c1,c2;
    if(nivS==nivT)
    {
        vector<int> cand;
        for(int i=0;i<n;i++)
            if(niv[i]==nivS)
                cand.push_back(i);
        while(true)
        {
            if(cand.size()==2)
            {
                c1.push_back(cand[0]);
                c2.push_back(cand[1]);
                break;
            }
            vector<int> x,y;
            int lg=cand.size();
            for(int i=0;i<cand.size();i++)
            {
                if(i<lg/2)
                    x.push_back(cand[i]);
                else
                    y.push_back(cand[i]);
            }
            for(int i=0;i<m;i++)
                w[i]=1;
            for(int i:x)
                w[topar[i]]=0;
            calls++;
            //assert(calls<=60);
            ll val=ask(w);
            if(val==1LL*(dist-2)*B+2LL*A)
            {
                cand=x;
                continue;
            }
            if(val==dist*B)
            {
                cand=y;
                continue;
            }
            c1=x;
            c2=y;
            break;
        }
    }
    else
    {
        for(int i=0;i<n;i++)
        {
            if(niv[i]==nivS)
                c1.push_back(i);
            if(niv[i]==nivT)
                c2.push_back(i);
        }
    }
    int T=getnode(c2);
    if(nivS!=nivT)
    {
        c1.clear();
        for(int i=0;i<n;i++)
            if(niv[i]==nivS&&niv[LCA(i,T)]==nivlca)
                c1.push_back(i);
    }
    int S=getnode(c1);
    //assert(S!=T);
    //assert(S!=-1&&T!=-1);
    answer(S,T);
}

Compilation message

highway.cpp: In function 'int getnode(std::vector<int>)':
highway.cpp:76:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   76 |         for(int i=0;i<cand.size();i++)
      |                     ~^~~~~~~~~~~~
highway.cpp: In function 'void find_pair(int, std::vector<int>, std::vector<int>, int, int)':
highway.cpp:178:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  178 |             for(int i=0;i<cand.size();i++)
      |                         ~^~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 12632 KB Output is correct
2 Correct 2 ms 12632 KB Output is correct
3 Correct 2 ms 12632 KB Output is correct
4 Correct 2 ms 12632 KB Output is correct
5 Correct 2 ms 12632 KB Output is correct
6 Correct 2 ms 12632 KB Output is correct
7 Correct 2 ms 12632 KB Output is correct
8 Correct 2 ms 12632 KB Output is correct
9 Correct 2 ms 12632 KB Output is correct
10 Correct 2 ms 12632 KB Output is correct
11 Correct 2 ms 12632 KB Output is correct
12 Correct 2 ms 12884 KB Output is correct

Subtask #2
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 12632 KB Output is correct
2 Correct 9 ms 13584 KB Output is correct
3 Correct 84 ms 20060 KB Output is correct
4 Correct 85 ms 20048 KB Output is correct
5 Correct 85 ms 20300 KB Output is correct
6 Correct 92 ms 20120 KB Output is correct
7 Correct 86 ms 19836 KB Output is correct
8 Correct 85 ms 20052 KB Output is correct
9 Correct 103 ms 20060 KB Output is correct
10 Correct 82 ms 19844 KB Output is correct
11 Correct 100 ms 21628 KB Output is correct
12 Correct 119 ms 21576 KB Output is correct
13 Correct 99 ms 21636 KB Output is correct
14 Correct 110 ms 20760 KB Output is correct

Subtask #3
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 14292 KB Output is correct
2 Correct 17 ms 15448 KB Output is correct
3 Correct 23 ms 16536 KB Output is correct
4 Correct 78 ms 22632 KB Output is correct
5 Correct 69 ms 24136 KB Output is correct
6 Correct 83 ms 25096 KB Output is correct
7 Correct 70 ms 23812 KB Output is correct
8 Correct 76 ms 23448 KB Output is correct
9 Correct 74 ms 22592 KB Output is correct

Subtask #4
0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 12848 KB Output is correct
2 Correct 9 ms 13576 KB Output is correct
3 Correct 60 ms 18620 KB Output is correct
4 Correct 86 ms 20076 KB Output is correct
5 Correct 79 ms 19836 KB Output is correct
6 Correct 86 ms 20308 KB Output is correct
7 Correct 81 ms 19840 KB Output is correct
8 Correct 85 ms 19836 KB Output is correct
9 Correct 85 ms 20284 KB Output is correct
10 Correct 96 ms 19844 KB Output is correct
11 Correct 105 ms 21444 KB Output is correct
12 Correct 100 ms 21476 KB Output is correct
13 Correct 104 ms 22024 KB Output is correct
14 Correct 105 ms 21752 KB Output is correct
15 Correct 81 ms 20052 KB Output is correct
16 Correct 86 ms 20524 KB Output is correct
17 Correct 99 ms 20880 KB Output is correct
18 Correct 97 ms 21236 KB Output is correct
19 Correct 73 ms 19832 KB Output is correct
20 Correct 102 ms 21384 KB Output is correct
21 Correct 73 ms 21228 KB Output is correct
22 Correct 80 ms 21000 KB Output is correct
23 Correct 87 ms 20760 KB Output is correct
24 Correct 100 ms 21416 KB Output is correct
25 Runtime error 126 ms 43960 KB Execution killed with signal 6
26 Halted 0 ms 0 KB -

Subtask #5
0 / 18.0

# Verdict Execution time Memory Grader output
1 Runtime error 745 ms 262144 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -

Subtask #6
0 / 31.0

# Verdict Execution time Memory Grader output
1 Runtime error 538 ms 262144 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -