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답안 #879559

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
879559 2023-11-27T16:21:03 Z andrei_boaca 통행료 (IOI18_highway) C++17
18 / 100
 752 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;
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;
}
void buildniv(int 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;
    }
}
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;
        buildniv(mij);
        ll val=ask(w);
        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;
        buildniv(mij);
        ll nra=2*(mij-nivlca);
        if(nra<=dist)
        {
            ll val=ask(w);
            buildniv(mij-1);
            ll val2=ask(w);
            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:69:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   69 |         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:170:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  170 |             for(int i=0;i<cand.size();i++)
      |                         ~^~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 12888 KB Output is correct
2 Correct 2 ms 12888 KB Output is correct
3 Correct 2 ms 12888 KB Output is correct
4 Correct 2 ms 12888 KB Output is correct
5 Correct 2 ms 12888 KB Output is correct
6 Correct 2 ms 12888 KB Output is correct
7 Correct 2 ms 12888 KB Output is correct
8 Correct 2 ms 12884 KB Output is correct
9 Correct 2 ms 12888 KB Output is correct
10 Correct 2 ms 12888 KB Output is correct
11 Correct 2 ms 12888 KB Output is correct
12 Correct 2 ms 12888 KB Output is correct

Subtask #2
7.0 / 7.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 12888 KB Output is correct
2 Correct 12 ms 13828 KB Output is correct
3 Correct 95 ms 19528 KB Output is correct
4 Correct 108 ms 19748 KB Output is correct
5 Correct 92 ms 19512 KB Output is correct
6 Correct 90 ms 19648 KB Output is correct
7 Correct 98 ms 19744 KB Output is correct
8 Correct 114 ms 19504 KB Output is correct
9 Correct 91 ms 19288 KB Output is correct
10 Correct 115 ms 19532 KB Output is correct
11 Correct 139 ms 20260 KB Output is correct
12 Correct 109 ms 21056 KB Output is correct
13 Correct 164 ms 21416 KB Output is correct
14 Correct 125 ms 20668 KB Output is correct

Subtask #3
6.0 / 6.0

# 결과 실행 시간 메모리 Grader output
1 Correct 9 ms 14256 KB Output is correct
2 Correct 18 ms 15316 KB Output is correct
3 Correct 31 ms 16676 KB Output is correct
4 Correct 92 ms 23972 KB Output is correct
5 Correct 83 ms 23328 KB Output is correct
6 Correct 93 ms 21888 KB Output is correct
7 Correct 71 ms 22548 KB Output is correct
8 Correct 119 ms 23024 KB Output is correct
9 Correct 77 ms 23480 KB Output is correct

Subtask #4
0 / 33.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 12888 KB Output is correct
2 Correct 11 ms 13824 KB Output is correct
3 Correct 63 ms 18244 KB Output is correct
4 Correct 98 ms 19272 KB Output is correct
5 Correct 106 ms 19528 KB Output is correct
6 Correct 97 ms 19532 KB Output is correct
7 Correct 123 ms 19276 KB Output is correct
8 Correct 95 ms 19516 KB Output is correct
9 Correct 127 ms 19520 KB Output is correct
10 Correct 104 ms 19520 KB Output is correct
11 Correct 106 ms 20700 KB Output is correct
12 Correct 120 ms 21372 KB Output is correct
13 Correct 98 ms 20796 KB Output is correct
14 Correct 110 ms 20984 KB Output is correct
15 Correct 107 ms 19556 KB Output is correct
16 Correct 84 ms 19324 KB Output is correct
17 Correct 122 ms 21224 KB Output is correct
18 Correct 113 ms 20464 KB Output is correct
19 Correct 81 ms 19280 KB Output is correct
20 Correct 99 ms 21036 KB Output is correct
21 Correct 88 ms 20480 KB Output is correct
22 Correct 99 ms 20224 KB Output is correct
23 Incorrect 100 ms 20152 KB Output isn't correct
24 Halted 0 ms 0 KB -

Subtask #5
0 / 18.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 752 ms 262144 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -

Subtask #6
0 / 31.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 487 ms 262144 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -