Submission #43542

#	Time	Username	Problem	Language	Result	Execution time	Memory
43542		wxh010910	Commuter Pass (JOI18_commuter_pass)	C++14	100 / 100	416 ms	142152 KiB

commuter_pass

#include <bits/stdc++.h>

using namespace std;

#define X first
#define Y second
#define mp make_pair
#define pb push_back
#define Debug(...) fprintf(stderr, __VA_ARGS__)

typedef long long LL;
typedef long double LD;
typedef unsigned int uint;
typedef pair <int, int> pii;
typedef unsigned long long uLL;

template <typename T> inline void Read(T &x) {
  char c = getchar();
  bool f = false;
  for (x = 0; !isdigit(c); c = getchar()) {
    if (c == '-') {
      f = true;
    }
  }
  for (; isdigit(c); c = getchar()) {
    x = x * 10 + c - '0';
  }
  if (f) {
    x = -x;
  }
}

template <typename T> inline bool CheckMax(T &a, const T &b) {
  return a < b ? a = b, true : false;
}

template <typename T> inline bool CheckMin(T &a, const T &b) {
  return a > b ? a = b, true : false;
}

const int N = 100005;
const LL inf = 1LL << 60;

LL ans, f[N], g[N], S[N], T[N], U[N], V[N];
priority_queue <pair <LL, int>> q;
int n, m, s, t, u, v, top, seq[N];
vector <pii> adj[N];
bool vis[N];

inline void Dijkstra(int s, LL *d) {
  for (int i = 1; i <= n; ++i) {
    vis[i] = false, d[i] = inf;
  }
  d[s] = 0, q.push(mp(0, s));
  while (!q.empty()) {
    int x = q.top().Y;
    q.pop();
    if (vis[x]) {
      continue;
    }
    vis[x] = true;
    for (auto e : adj[x]) {
      if (CheckMin(d[e.X], d[x] + e.Y)) {
        q.push(mp(-d[e.X], e.X));
      }
    }
  }
}

int main() {
#ifdef wxh010910
  freopen("d.in", "r", stdin);
#endif
  Read(n), Read(m), Read(s), Read(t), Read(u), Read(v);
  for (int i = 1, x, y, w; i <= m; ++i) {
    Read(x), Read(y), Read(w);
    adj[x].pb(mp(y, w)), adj[y].pb(mp(x, w));
  }
  Dijkstra(s, S), Dijkstra(t, T), Dijkstra(u, U), Dijkstra(v, V), ans = u[V];
  for (int i = 1; i <= n; ++i) {
    if (S[i] + T[i] == S[t]) {
      seq[++top] = i, f[i] = U[i], g[i] = V[i];
    }
  }
  sort(seq + 1, seq + top + 1, [&](const int &x, const int &y) {
    return S[x] < S[y];
  });
  for (int i = 1; i <= top; ++i) {
    int x = seq[i];
    for (auto e : adj[x]) {
      if (S[e.X] + e.Y == S[x]) {
        CheckMin(f[x], f[e.X]), CheckMin(g[x], g[e.X]);
      }
    }
    CheckMin(ans, f[x] + V[x]), CheckMin(ans, g[x] + U[x]);
  }
  printf("%lld\n", ans);
#ifdef wxh010910
  Debug("My Time: %.3lfms\n", (double)clock() / CLOCKS_PER_SEC);
#endif
  return 0;
}

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