Submission #170984

#	Time	Username	Problem	Language	Result	Execution time	Memory
170984		Rods	Toll (BOI17_toll)	C++14	0 / 100	3020 ms	12892 KiB

toll

#include <bits/stdc++.h>
#define endl '\n'
#define all(x) x.begin(),x.end()
#define sz(x) ((int)x.size())
#define x first
#define y second
#define pb push_back
#define ppb pop_back
#define pf push_front
#define ppf pop_front
#define ll long long
#define int ll
#define ld long double
#define ii pair<int, int>
#define iii pair<int, ii>
#define vi vector<int>
#define vii vector<ii>
using namespace std;
const int ms = 5e4+100;
const int inf = 1e15;
const int sigma = 8;
const int mlg = 23;
int n, m, k, t, q;
 
vii g[ms];
int dis[ms][sigma];
int adj[ms];
priority_queue<ii, vector<ii>, greater<ii>> pq;
 
void dijkstra(int x, int p) {
  dis[x][p] = 0;
  pq.push(ii(0, x));
  while(!pq.empty()) {
    ii x = pq.top(); pq.pop();
    int u = x.second;
    if(x.first > dis[u][p]) continue;
    for(auto e : g[u]) {
      int v = e.first, w = e.second;
      if(dis[u][p]+w < dis[v][p]) {
        dis[v][p] = dis[u][p] + w;
        pq.push(ii(dis[v][p], v));
      }
    }
  }
}

void is_conected(int a, int b, set<int> &vis){
  if(a/k > b/k) return;
  vis.insert(a);
  for(auto x: g[a]){
    if(vis.count(x.x)==0) is_conected(x.x, b, vis);
  }
}
 
void solve(){
  for(int i=0; i<ms; i++){
    for(int j=0; j<sigma; j++)
      dis[i][j] = inf;
  }
  cin>>k>>n>>m>>q;
  int a, b, c;
  for(int i=0; i<m; i++){
    cin>>a>>b>>c;
    adj[b]++;
    g[a].pb({b, c});
  }
  for(int i=0; i<n; i++){
    if(adj[i]==0){
      // g[n+i%k].pb({i, 0});
    }
  }

  for(int i=0; i<n; i++){
    if(dis[i][0]==inf){
      dijkstra(i, 0);
    }
  }
  while(q--){
    cin>>a>>b;
    set<int> aux;
    is_conected(a, b, aux);
    if(aux.count(b)){
      cout<<dis[b][0] - dis[a][0]<<endl;
    }else{
      cout<<-1<<endl;
    }
  }
}
 
int32_t main(){
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  solve();
}

• Subtask 1: 0 / 7
• Subtask 2: 0 / 10
• Subtask 3: 0 / 8
• Subtask 4: 0 / 31
• Subtask 5: 0 / 44