oj.uz

Submission #364307

# Submission time Handle Problem Language Result Execution time Memory
364307 2021-02-08T21:06:05 Z tushar_2658 Olympic Bus (JOI20_ho_t4) C++14
0 / 100
 192 ms 6108 KB 
#include "bits/stdc++.h"
using namespace std;

const int maxn = 205;
using ll = long long;
ll inf = 1e16;

struct E {
  int x, id;
  ll c, d;
  E(int _x, ll _c, ll _d, int _id){
    x = _x, c = _c, d = _d;
    id = _id;
  }
  E(){}
};

vector<E> edges[maxn], g[maxn];
ll dis[2][maxn];
int par[2][maxn];
vector<int> candidates;
int n, m;

void dijkstra(int id, int s){
  for(int i = 1; i <= n; ++i)dis[id][i] = inf;
  dis[id][s] = 0;
  using pii = pair<ll, ll>;
  priority_queue<pii, vector<pii>, greater<pii>> pq;
  pq.push({0, s});
  vector<bool> vis(n + 1);
  while(!pq.empty()){
    pii src = pq.top();
    pq.pop();
    if(vis[src.second])continue;
    vis[src.second] = 1;
    for(auto i : edges[src.second]){
      ll cost = dis[id][src.second] + i.c;
      if(dis[id][i.x] > cost){
        dis[id][i.x] = cost;
        par[id][i.x] = i.id;
        pq.push({cost, i.x});
      }
    }
  }
}

ll ans = inf;
ll dis1[2][maxn];

void dijkstra1(int id, int s){
  for(int i = 1; i <= n; ++i)dis1[id][i] = inf;
  dis1[id][s] = 0;
  using pii = pair<ll, ll>;
  priority_queue<pii, vector<pii>, greater<pii>> pq;
  pq.push({0, s});
  vector<bool> vis(n + 1);
  while(!pq.empty()){
    pii src = pq.top();
    pq.pop();
    if(vis[src.second])continue;
    vis[src.second] = 1;
    for(auto i : g[src.second]){
      ll cost = dis1[id][src.second] + i.c;
      if(dis1[id][i.x] > cost){
        dis1[id][i.x] = cost;
        pq.push({cost, i.x});
      }
    }
  }
}

ll check(int id){
  ll D = 0;
  for(int i = 1; i <= n; ++i)g[i].clear();
  for(int i = 1; i <= n; ++i){
    for(auto j : edges[i]){
      if(j.id != id){
        g[i].push_back(j);
      }else {
        g[j.x].push_back(E(i, j.c, j.d, j.id));
        D = j.d;
      }
    }
  }
  dijkstra1(0, 1);
  dijkstra1(1, n);
  return D + dis1[0][n] + dis1[1][1];
}

int good[50005];
ll dis2[maxn][maxn];

void floyd(){
  for(int k = 1; k <= n; ++k){
    for(int i = 1; i <= n; ++i){
      for(int j = 1; j <= n; ++j){
        if(dis2[i][k] + dis2[k][j] < dis2[i][j]){
          dis2[i][j] = dis2[i][k] + dis2[k][j];
        }
      }
    }
  }
}

int main(int argc, char const *argv[])
{
  ios::sync_with_stdio(false);
  cin.tie(0);

  cin >> n >> m;
  using pii = pair<ll, ll>;
  vector<pair<pii, pii>> inp;
  for(int i = 1; i <= n; ++i)for(int j = 1; j <= n; ++j)dis2[i][j] = inf;
  for(int i = 0; i < m; ++i){
    int u, v;
    ll C, D;
    cin >> u >> v >> C >> D;
    edges[u].push_back(E(v, C, D, i));
    inp.push_back({{u, v}, {C, D}});
    dis2[u][v] = min(dis2[u][v], C);
  }
  memset(par, -1, sizeof par);
  dijkstra(0, 1);
  dijkstra(1, n);
  floyd();
  for(int i = 0; i < 2; ++i){
    for(int j = 1; j <= n; ++j){
      if(par[i][j] != -1){
        candidates.push_back({par[i][j]});
      }
    }
  }
  sort(candidates.begin(), candidates.end());
  candidates.erase(unique(candidates.begin(), candidates.end()), candidates.end());
  ans = 1e18;
  if(dis[0][n] < inf && dis[1][1] < inf)ans = dis[0][n] + dis[1][1];
  for(auto i : candidates){
    ans = min(ans, check(i));
    good[i] = 1;
  }
  for(int i = 0; i < m; ++i){
    if(!good[i]){
      ll x = 1e18, y = 1e18;
      if(dis[0][n] < inf)x = dis[0][n];
      if(dis2[1][inp[i].first.second] < inf && dis2[inp[i].first.first][n] < inf)x = min(x, dis2[1][inp[i].first.second] + dis2[inp[i].first.first][n] + inp[i].second.first);
      if(dis[1][1] < inf)y = dis[1][1];
      if(dis2[n][inp[i].first.second] < inf && dis2[inp[i].first.first][1] < inf)y = min(y, dis2[n][inp[i].first.second] + dis2[inp[i].first.first][1] + inp[i].second.first);
      ans = min(ans, x + y + inp[i].second.second);
    }
  }
  cout << (ans < inf ? ans : -1) << '\n';

  return 0;
}

Subtask #1
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 19 ms 748 KB Output is correct
2 Correct 9 ms 760 KB Output is correct
3 Correct 28 ms 748 KB Output is correct
4 Correct 30 ms 876 KB Output is correct
5 Correct 2 ms 492 KB Output is correct
6 Correct 9 ms 748 KB Output is correct
7 Correct 0 ms 364 KB Output is correct
8 Correct 1 ms 364 KB Output is correct
9 Incorrect 1 ms 492 KB Output isn't correct
10 Halted 0 ms 0 KB -

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 188 ms 5848 KB Output is correct
2 Correct 192 ms 5980 KB Output is correct
3 Correct 188 ms 5852 KB Output is correct
4 Incorrect 28 ms 876 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 748 KB Output is correct
2 Correct 10 ms 748 KB Output is correct
3 Correct 130 ms 4572 KB Output is correct
4 Correct 9 ms 748 KB Output is correct
5 Correct 158 ms 5724 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 0 ms 364 KB Output is correct
8 Correct 83 ms 6108 KB Output is correct
9 Correct 89 ms 5980 KB Output is correct
10 Correct 125 ms 5724 KB Output is correct
11 Correct 120 ms 5852 KB Output is correct
12 Correct 129 ms 6108 KB Output is correct
13 Correct 0 ms 364 KB Output is correct
14 Correct 0 ms 364 KB Output is correct
15 Correct 1 ms 364 KB Output is correct
16 Incorrect 1 ms 364 KB Output isn't correct
17 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 19 ms 748 KB Output is correct
2 Correct 9 ms 760 KB Output is correct
3 Correct 28 ms 748 KB Output is correct
4 Correct 30 ms 876 KB Output is correct
5 Correct 2 ms 492 KB Output is correct
6 Correct 9 ms 748 KB Output is correct
7 Correct 0 ms 364 KB Output is correct
8 Correct 1 ms 364 KB Output is correct
9 Incorrect 1 ms 492 KB Output isn't correct
10 Halted 0 ms 0 KB -