Submission #494784

#	Time	Username	Problem	Language	Result	Execution time	Memory
494784		kamalsharmaa9	Commuter Pass (JOI18_commuter_pass)	C++14	100 / 100	398 ms	23988 KiB

commuter_pass

//https://pastebin.com/jVURaNCJ
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
using namespace std;

#define N               100005
#define ff              first
#define ss              second
#define int             long long
#define pb              push_back
#define mp              make_pair
#define pii             pair<int,int>
#define piii            pair<pair<int,int>,pair<int,int>>
#define vi              vector<int>
#define mii             map<int,int>
#define pqb             priority_queue<int>
#define pqs             priority_queue<int,vi,greater<int> >
#define setbits(x)      __builtin_popcountll(x)
#define zrobits(x)      __builtin_ctzll(x)
#define mod             1000000007
#define inf             1e18
#define ps(x,y)         fixed<<setprecision(y)<<x
#define mk(arr,n,type)  type *arr=new type[n];
#define w(x)            int x; cin>>x; while(x--)
mt19937                 rng(chrono::steady_clock::now().time_since_epoch().count());

typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> pbds;


void c_p_c()
{
  ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);



}
int du[N];
int dv[N];
int ans = inf;
vector<pii>gr[N];
void dijkstra1(int node, int n, int  dist[])
{
  for (int i = 0; i <= n; i++)
    dist[i] = inf;
  dist[node] = 0;
  priority_queue<pii, vector<pii>, greater<pii>>q;
  q.push({dist[node], node});
  int val;
  while (!q.empty())
  {

    node = q.top().ss;
    val = q.top().ff;
    q.pop();
    if (dist[node] < val)
      continue;
    for (auto child : gr[node])
    {
      if (dist[child.ff] > dist[node] + child.ss)
      {
        dist[child.ff] = dist[node] + child.ss;
        q.push({dist[child.ff], child.ff});
      }

    }
  }
}
int dist[N];
int dist2[2][N];
void dijkstra2(int node, int n, int end)
{

  for (int i = 0; i <= n; i++)
  {
    dist[i] = dist2[0][i] = dist2[1][i] = inf;
  }
  dist[node] = 0;
  priority_queue<pii, vector<pii>, greater<pii>>q;
  q.push({0, node});
  dist2[0][node] = du[node];
  dist2[1][node] = dv[node];
  while (!q.empty())
  {
    node = q.top().ss;
    int val = q.top().ff;
    q.pop();
    for (auto child : gr[node])
    {
      int to_com = min( dist2[0][node], du[child.ff]) + min(dist2[1][node], dv[child.ff]);
      if (dist[child.ff] > dist[node] + child.ss)
      {
        // cout << child.ff << endl;
        dist[child.ff] = dist[node] + child.ss;
        dist2[0][child.ff] = min(dist2[0][node], du[child.ff]);
        dist2[1][child.ff] = min(dist2[1][node], dv[child.ff]);
        q.push({dist[child.ff], child.ff});
      }
      else if (dist[child.ff] == dist[node] + child.ss && dist2[0][child.ff] + dist2[1][child.ff] > to_com)
      {

        dist2[0][child.ff] = min( dist2[0][node], du[child.ff]);
        dist2[1][child.ff] = min(dist2[1][node], dv[child.ff]);
      }
    }
  }
  ans = min(ans, dist2[0][end] + dist2[1][end]);
  //cout << dist2[0][7] << " " << dist2[1][7] << " " << dist2[0][2] << " " << dist2[1][2] << endl;
}
int32_t main()
{
  c_p_c();
  int n, m, s, t, u, v; cin >> n >> m >> s >> t >> u >> v;
  for (int i = 0; i < m; i++)
  {
    int a, b, c; cin >> a >> b >> c;
    gr[a].pb({b, c});
    gr[b].pb({a, c});

  }
  dijkstra1(u, n, du);
  dijkstra1(v, n, dv);
  ans = dv[u];
  dijkstra2(s, n, t);
  dijkstra2(t, n, s);
  cout << ans << '\n';
  return 0;
}

Compilation message (stderr)

commuter_pass.cpp: In function 'void dijkstra2(long long int, long long int, long long int)':
commuter_pass.cpp:86:9: warning: unused variable 'val' [-Wunused-variable]
   86 |     int val = q.top().ff;
      |         ^~~

• Subtask 1: 16 / 16
• Subtask 2: 15 / 15
• Subtask 3: 24 / 24
• Subtask 4: 45 / 45