oj.uz

Submission #879565

# Submission time Handle Problem Language Result Execution time Memory
879565 2023-11-27T16:23:40 Z andrei_boaca Highway Tolls (IOI18_highway) C++17
18 / 100
 750 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];
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;
    }
    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;
        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);
    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;
            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:74:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   74 |         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:172:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  172 |             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 12776 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 12756 KB Output is correct

Subtask #2
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 12632 KB Output is correct
2 Correct 15 ms 13580 KB Output is correct
3 Correct 109 ms 20052 KB Output is correct
4 Correct 101 ms 20052 KB Output is correct
5 Correct 110 ms 20060 KB Output is correct
6 Correct 109 ms 19820 KB Output is correct
7 Correct 77 ms 20064 KB Output is correct
8 Correct 91 ms 19816 KB Output is correct
9 Correct 78 ms 20060 KB Output is correct
10 Correct 81 ms 20064 KB Output is correct
11 Correct 112 ms 21408 KB Output is correct
12 Correct 138 ms 21568 KB Output is correct
13 Correct 119 ms 22016 KB Output is correct
14 Correct 102 ms 20752 KB Output is correct

Subtask #3
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 14112 KB Output is correct
2 Correct 17 ms 15112 KB Output is correct
3 Correct 25 ms 16428 KB Output is correct
4 Correct 77 ms 23612 KB Output is correct
5 Correct 62 ms 22600 KB Output is correct
6 Correct 99 ms 25096 KB Output is correct
7 Correct 71 ms 22372 KB Output is correct
8 Correct 83 ms 22588 KB Output is correct
9 Correct 87 ms 23212 KB Output is correct

Subtask #4
0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 12632 KB Output is correct
2 Correct 11 ms 13580 KB Output is correct
3 Correct 67 ms 18608 KB Output is correct
4 Correct 88 ms 19824 KB Output is correct
5 Correct 97 ms 19820 KB Output is correct
6 Correct 78 ms 20252 KB Output is correct
7 Correct 79 ms 19824 KB Output is correct
8 Correct 89 ms 20056 KB Output is correct
9 Correct 136 ms 20048 KB Output is correct
10 Correct 95 ms 19840 KB Output is correct
11 Correct 123 ms 21008 KB Output is correct
12 Correct 113 ms 21452 KB Output is correct
13 Correct 96 ms 21088 KB Output is correct
14 Correct 110 ms 21676 KB Output is correct
15 Correct 74 ms 20064 KB Output is correct
16 Correct 95 ms 20076 KB Output is correct
17 Correct 96 ms 21004 KB Output is correct
18 Correct 104 ms 21356 KB Output is correct
19 Correct 95 ms 19836 KB Output is correct
20 Correct 117 ms 21584 KB Output is correct
21 Correct 80 ms 20988 KB Output is correct
22 Correct 76 ms 20772 KB Output is correct
23 Correct 94 ms 21004 KB Output is correct
24 Incorrect 141 ms 20760 KB Output isn't correct
25 Halted 0 ms 0 KB -

Subtask #5
0 / 18.0

# Verdict Execution time Memory Grader output
1 Runtime error 750 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 557 ms 262144 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -