fork download
copy 
  1. #include <bits/stdc++.h>
  2. using namespace std;
  3. #define endl '\n'
  4. #define ull unsigned long long
  5. #define mod 1000000007
  6. #define pb push_back
  7. #define ll long long
  8. const ll INF = 1e18;
  9. ll n, m, k;
  10. ll d(ll w, const vector<vector<pair<ll, pair<ll, ll>>>>& adj) {
  11.     priority_queue<pair<ll, ll>, vector<pair<ll, ll>>, greater<pair<ll, ll>>> pq;
  12.     vector<ll> dis(n + 1, INF);
  13.     dis[1] = 0;
  14.     pq.push({0, 1});
  15.     while (!pq.empty()) {
  16.         ll cost = pq.top().first;
  17.         ll node = pq.top().second;
  18.         pq.pop();
  19.         if (cost > dis[node]) continue;
  20.         for (auto& edge : adj[node]) {
  21.             ll neigh = edge.first;
  22.             ll c = edge.second.first;
  23.             ll weight = edge.second.second;
  24.             if (weight > w) continue;
  25.             if (dis[neigh] > cost + c) {
  26.                 dis[neigh] = cost + c;
  27.                 pq.push({dis[neigh], neigh});
  28.             }
  29.         }
  30.     }
  31.     return dis[n];
  32. }
  33. int main() {
  34.     ios::sync_with_stdio(0);
  35.     cin.tie(0);
  36.     cout.tie(0);
  37.     int t;
  38.     cin >> t;
  39.     while (t--) {
  40.         cin >> n >> m >> k;
  41.         vector<vector<pair<ll, pair<ll, ll>>>> adj(n + 1);
  42.         for (int i = 0; i < m; i++) {
  43.             ll from, to, c, w;
  44.             cin >> from >> to >> c >> w;
  45.             adj[from].pb({to, {c, w}});
  46.             adj[to].pb({from, {c, w}});
  47.         }
  48.         if (n == 1) {
  49.             cout << "0" << endl;
  50.             continue;
  51.         }
  52.         if (m == 0) {
  53.             cout << "-1" << endl;
  54.             continue;
  55.         }
  56.         ll l = 0, r = 2e9, anss = -1;
  57.         while (l <= r) {
  58.             ll mid = l + (r - l) / 2;
  59.             ll cost = d(mid, adj);
  60.             if (cost < k) {
  61.                 anss = mid;
  62.                 r = mid - 1;
  63.             } else {
  64.                 l = mid + 1;
  65.             }
  66.         }
  67.         cout << anss << endl;
  68.     }
  69. }
  70.  
Success #stdin #stdout 0.01s 5280KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
Standard output is empty
https://ideone.com/LZ4syN
language:
C++14 (clang 8.0)
created:
12 days ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!