제출 #1156981

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1156981		mychecksedad	Construction Project 2 (JOI24_ho_t2)	C++20	100 / 100	257 ms	42412 KiB

Main

/* Author : Mychecksdead  */
#include<bits/stdc++.h>
using namespace std;
#define ll long long int
#define MOD (1000000000+7)
#define MOD1 (998244353)
#define pb push_back
#define all(x) x.begin(), x.end()
#define en cout << '\n'
#define ff first
#define ss second
#define pii pair<int,int>
#define vi vector<int>
const int N = 1e6+100, M = 1e5+10, K = 52, MX = 30;


ll n, m, s, t, k, l;
vector<pair<int, ll>> g[N];
void solve(){
  cin >> n >> m >> s >> t >> l >> k;
  --s,--t;
  for(int i = 1; i <= m; ++i){
    int u, v, w; cin >>u >> v >> w;
    --u,--v;
    g[u].pb({v, w});
    g[v].pb({u, w});
  }
  priority_queue<pair<ll,int>>Q;
  vector<ll> dist(n, (ll)1e18*1ll);
  vector<ll> dist2(n, (ll)1e18*1ll);
  vector<bool> used(n);
  Q.push({0, s});
  dist[s] = 0;
  while(!Q.empty()){
    int v = Q.top().ss; Q.pop();
    if(used[v]) continue;
    used[v] = 1;
    for(auto [u, w]: g[v]){
      if(dist[u] > dist[v] + w){
        dist[u] = dist[v] + w;
        Q.push({-dist[u], u});
      }
    }
  }
  fill(all(used), 0);
  Q.push({0, t});
  dist2[t] = 0;
  while(!Q.empty()){
    int v = Q.top().ss; Q.pop();
    if(used[v]) continue;
    used[v] = 1;
    for(auto [u, w]: g[v]){
      if(dist2[u] > dist2[v] + w){
        dist2[u] = dist2[v] + w;
        Q.push({-dist2[u], u});
      }
    }
  }
  if(dist[t] <= k){
    cout << n*(n-1)/2;
  }else{
    ll ans=0;
    sort(all(dist));
    sort(all(dist2));
    for(ll x: dist){
      ans += upper_bound(all(dist2), k - l - x) - dist2.begin();
    }
    cout<<ans;
  }
}


int main(){
  cin.tie(0); ios::sync_with_stdio(0);
  int tt = 1, aa;
  // freopen("in.txt", "r", stdin);
  // freopen("out.txt", "w", stdout);
  while(tt--){
    solve();
    en;
  }
  cerr<<"time taken : "<<(float)clock()/CLOCKS_PER_SEC<<" seconds\n";
  return 0;
} 

• Subtask 1: 8 / 8
• Subtask 2: 16 / 16
• Subtask 3: 29 / 29
• Subtask 4: 47 / 47