Problem p02703 (C++)

Buggy submission (status: Time Limit Exceeded):
// <head>
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int INF = 1002003004;
const ll LINF = 1002003004005006007ll;
struct preprocess {
  preprocess() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(20);
  }
} ____;
// </head>

// <library>

// </library>

struct Edge {
  ll to, a, b;
  Edge(ll to, ll a, ll b) : to(to), a(a), b(b) {}
};
const ll MAXV = 50;
const ll MAXS = MAXV * 50 + 5;
vector<Edge> g[MAXV];
ll dp[MAXV][MAXS + 5];

struct Data {
  ll s, v, t;
  Data(ll v, ll s, ll t) : v(v), s(s), t(t) {}
  bool operator<(const Data &a) const { return t > a.t; }
};
int main() {
  ll n, m, s;
  cin >> n >> m >> s;

  for (int i = 0; i < m; i++) {
    int u, v, a, b;
    cin >> u >> v >> a >> b;
    u--;
    v--;
    g[u].emplace_back(v, a, b);
    g[v].emplace_back(u, a, b);
  }
  vector<ll> c(n), d(n);
  for (int i = 0; i < n; i++) {
    cin >> c[i] >> d[i];
  }
  for (int i = 0; i < MAXV; i++) {
    for (int j = 0; j < MAXS; j++) {
      dp[i][j] = LINF;
    }
  }
  s = min(s, MAXS);

  priority_queue<Data> q;
  dp[0][s] = 0;
  q.emplace(0, s, 0);
  while (!q.empty()) {
    Data dt = q.top();
    q.pop();
    if (dp[dt.v][dt.s] < dt.t)
      continue;
    if (dt.s < 0)
      continue;

    // exchange
    ll ns = min(MAXS, dt.s + c[dt.v]);
    dp[dt.v][ns] = min(dp[dt.v][ns], dt.t + d[dt.v]);
    q.emplace(dt.v, ns, dt.t + d[dt.v]);

    // move to other station
    for (Edge e : g[dt.v]) {
      if (dt.s - e.a >= 0 && dp[e.to][dt.s - e.a] > dp[dt.v][dt.s] + e.b) {
        dp[e.to][dt.s - e.a] = dp[dt.v][dt.s] + e.b;
        q.emplace(e.to, dt.s - e.a, dp[e.to][dt.s - e.a]);
      }
    }
  }
  for (int i = 1; i < n; i++) {
    ll ans = LINF;
    for (int j = 0; j < MAXS; j++) {
      ans = min(ans, dp[i][j]);
    }
    cout << ans << '\n';
  }
}

Fixed submission:
// <head>
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int INF = 1002003004;
const ll LINF = 1002003004005006007ll;
struct preprocess {
  preprocess() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(20);
  }
} ____;
// </head>

// <library>

// </library>

struct Edge {
  ll to, a, b;
  Edge(ll to, ll a, ll b) : to(to), a(a), b(b) {}
};
const ll MAXV = 50;
const ll MAXS = MAXV * 50 + 5;
vector<Edge> g[MAXV];
ll dp[MAXV][MAXS + 5];

struct Data {
  ll s, v, t;
  Data(ll v, ll s, ll t) : v(v), s(s), t(t) {}
  bool operator<(const Data &a) const { return t > a.t; }
};
int main() {
  ll n, m, s;
  cin >> n >> m >> s;

  for (int i = 0; i < m; i++) {
    int u, v, a, b;
    cin >> u >> v >> a >> b;
    u--;
    v--;
    g[u].emplace_back(v, a, b);
    g[v].emplace_back(u, a, b);
  }
  vector<ll> c(n), d(n);
  for (int i = 0; i < n; i++) {
    cin >> c[i] >> d[i];
  }
  for (int i = 0; i < MAXV; i++) {
    for (int j = 0; j < MAXS; j++) {
      dp[i][j] = LINF;
    }
  }
  s = min(s, MAXS);

  priority_queue<Data> q;
  dp[0][s] = 0;
  q.emplace(0, s, 0);
  while (!q.empty()) {
    Data dt = q.top();
    q.pop();
    if (dp[dt.v][dt.s] < dt.t)
      continue;
    if (dt.s < 0)
      continue;

    // exchange
    ll ns = min(MAXS, dt.s + c[dt.v]);
    if (dp[dt.v][ns] > dt.t + d[dt.v]) {
      dp[dt.v][ns] = dt.t + d[dt.v];
      q.emplace(dt.v, ns, dt.t + d[dt.v]);
    }

    // move to other station
    for (Edge e : g[dt.v]) {
      if (dt.s - e.a >= 0 && dp[e.to][dt.s - e.a] > dp[dt.v][dt.s] + e.b) {
        dp[e.to][dt.s - e.a] = dp[dt.v][dt.s] + e.b;
        q.emplace(e.to, dt.s - e.a, dp[e.to][dt.s - e.a]);
      }
    }
  }
  for (int i = 1; i < n; i++) {
    ll ans = LINF;
    for (int j = 0; j < MAXS; j++) {
      ans = min(ans, dp[i][j]);
    }
    cout << ans << '\n';
  }
}