oj.uz

답안 #412918

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
412918 2021-05-27T19:21:31 Z LouayFarah 꿈 (IOI13_dreaming) C++14
0 / 100
 75 ms 65540 KB 
#include "bits/stdc++.h"
#include "dreaming.h"
using namespace std;
 
#define pb push_back
#define mp make_pair
#define fi first
#define se second
 
void dfs1(vector<pair<int, int>> adj[], vector<bool> &visited, int u)
{
    if(visited[u])
        return;
    visited[u] = true;
 
    for(auto v: adj[u])
    {
        dfs1(adj, visited, v.fi);
    }
}
 
pair<int, int> extract_components(vector<pair<int, int>> adj[], int N)
{
    vector<int> temp;
    vector<bool> visited(N, false);
 
    for(int i = 0; i<N; i++)
    {
        if(!visited[i])
        {
            dfs1(adj, visited, i);
            temp.pb(i);
        }
    }
 
    pair<int, int> res;
    res.fi = temp[0], res.se = temp[1];
    return res;
}
 
void depth(vector<pair<int, int>> adj[], vector<bool> visited, vector<int> &cnt, int u)
{
    visited[u] = true;
    for(auto v: adj[u])
    {
        if(!visited[v.fi])
        {
            cnt[v.fi] = cnt[u] + v.se;
            depth(adj, visited, cnt, v.fi);
        }
    }
}
 
pair<int, int> diameter(vector<pair<int, int>> adj[], int N, int u)
{
    int a = u, b, c;
 
    int maxi = 0;
    vector<bool> visited(N, false);
    vector<int> cnt(N, 0);
    depth(adj, visited, cnt, a);
    for(int i = 0; i<N; i++)
    {
        if(maxi<cnt[i])
        {
            maxi = cnt[i];
            b = i;
        }
    }
 
    cnt.assign(N, 0);
    visited.assign(N, false);
    depth(adj, visited, cnt, b);
    maxi = 0;
    for(int i = 0; i<N; i++)
    {
        if(maxi<cnt[i])
        {
            maxi = cnt[i];
            c = i;
        }
    }
 
    return mp(b, c);
}
 
vector<int> bfs(vector<pair<int, int>> adj[], int N, pair<int, int> d)
{
    int st = d.fi, en = d.se;
    vector<bool> visited(N, false);
    vector<int> parent(N, -1);
    queue<int> q;
    q.push(st);
    visited[st] = true;
 
    bool flag = true;
    while(!q.empty()&&flag)
    {
        int u  = q.front();
        q.pop();
 
        for(auto v: adj[u])
        {
            if(visited[v.fi])
                continue;
            visited[v.fi] = true;
            parent[v.fi] = u;
            q.push(v.fi);
            if(v.fi==en)
                flag = false;
        }
    }
 
    vector<int> path;
    while(parent[en]!=-1)
    {
        path.pb(en);
        en = parent[en];
    }
 
    path.pb(st);
    reverse(path.begin(), path.end());
    return path;
}
 
int solve(vector<pair<int, int>> adj[], int N)
{
    int a = 0, b;
 
    int maxi = 0;
    vector<bool> visited(N, false);
    vector<int> cnt(N, 0);
    depth(adj, visited, cnt, a);
    for(int i = 0; i<N; i++)
    {
        if(maxi<cnt[i])
        {
            maxi = cnt[i];
            b = i;
        }
    }
 
    cnt.assign(N, 0);
    visited.assign(N, false);
    depth(adj, visited, cnt, b);
    maxi = 0;
    for(int i = 0; i<N; i++)
    {
        if(maxi<cnt[i])
        {
            maxi = cnt[i];
        }
    }
 
    return maxi;
}
 
int travelTime(int N, int M, int L, int A[], int B[], int T[])
{
    vector<pair<int, int>> adj[N];
    for(int i = 0; i<M; i++)
    {
        adj[A[i]].pb(mp(B[i], T[i]));
        adj[B[i]].pb(mp(A[i], T[i]));
    }
 
    pair<int, int> comps = extract_components(adj, N);
    int a = comps.fi, b = comps.se;
 
    pair<int, int> d1 = diameter(adj, N, a);
    pair<int, int> d2 = diameter(adj, N, b);
 
    vector<int> path1, path2;
    path1 = bfs(adj, N, d1);
    path2 = bfs(adj, N, d2);
 
    int len1 = int(path1.size());
    int len2 = int(path2.size());
 
    vector<bool> visited(N, false);
    vector<int> cnt1(N, 0), cnt2(N, 0);
    depth(adj, visited, cnt1, path1[0]);
    depth(adj, visited, cnt2, path2[0]);
 
    int n1 = path1[0], n2 = path2[0];
 
    int dif = 1e8;
    for(int i = 1; i<len1; i++)
    {
        if(abs(cnt1[path1[i]]-(cnt1[path1[len1-1]]-cnt1[path1[i]]))<dif)
        {
            dif = abs(cnt1[path1[i]]-(cnt1[path1[len1-1]]-cnt1[path1[i]]));
            n1 = path1[i];
        }
    }
 
    dif = 1e8;
    for(int i = 1; i<len2; i++)
    {
        if(abs(cnt2[path2[i]]-(cnt2[path2[len2-1]]-cnt2[path2[i]]))<dif)
        {
            dif = abs(cnt2[path2[i]]-(cnt2[path2[len2-1]]-cnt2[path2[i]]));
            n2 = path2[i];
        }
    }
 
    /*for(auto elt: path1)
        cout << elt << ' ';
    cout << endl;
    for(auto elt: path2)
        cout << elt << ' ';
    cout << endl;
    cout << n1 << ' ' << n2 << endl;*/
 
    adj[n1].pb(mp(n2, L));
    adj[n2].pb(mp(n1, L));
 
    int res = solve(adj, N);
    return res;
}

Compilation message

dreaming.cpp: In function 'std::pair<int, int> diameter(std::vector<std::pair<int, int> >*, int, int)':
dreaming.cpp:56:19: warning: 'c' may be used uninitialized in this function [-Wmaybe-uninitialized]
   56 |     int a = u, b, c;
      |                   ^
dreaming.cpp:56:16: warning: 'b' may be used uninitialized in this function [-Wmaybe-uninitialized]
   56 |     int a = u, b, c;
      |                ^
dreaming.cpp: In function 'int solve(std::vector<std::pair<int, int> >*, int)':
dreaming.cpp:145:10: warning: 'b' may be used uninitialized in this function [-Wmaybe-uninitialized]
  145 |     depth(adj, visited, cnt, b);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 14.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 75 ms 65540 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -

Subtask #2
0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 1 ms 332 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -

Subtask #3
0 / 23.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 75 ms 65540 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -

Subtask #4
0 / 18.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 22 ms 6388 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0 / 12.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 1 ms 332 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -

Subtask #6
0 / 23.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 75 ms 65540 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -