Problem p02243 (C++)

Buggy submission (status: Runtime Error):
#include "bits/stdc++.h"
using namespace std;
using LL = long long;
using ULL = unsigned long long;
const double PI = acos(-1);
template <class T> constexpr T INF() { return ::std::numeric_limits<T>::max(); }
template <class T> constexpr T HINF() { return INF<T>() / 2; }
template <typename T_char> T_char TL(T_char cX) { return tolower(cX); };
template <typename T_char> T_char TU(T_char cX) { return toupper(cX); };
typedef pair<LL, LL> pii;
const int vy[] = {-1, -1, -1, 0, 1, 1, 1, 0},
          vx[] = {-1, 0, 1, 1, 1, 0, -1, -1};
const int dx[4] = {0, 1, 0, -1}, dy[4] = {1, 0, -1, 0};
int popcnt(unsigned long long n) {
  int cnt = 0;
  for (int i = 0; i < 64; i++)
    if ((n >> i) & 1)
      cnt++;
  return cnt;
}
int d_sum(LL n) {
  int ret = 0;
  while (n > 0) {
    ret += n % 10;
    n /= 10;
  }
  return ret;
}
int d_cnt(LL n) {
  int ret = 0;
  while (n > 0) {
    ret++;
    n /= 10;
  }
  return ret;
}
LL gcd(LL a, LL b) {
  if (b == 0)
    return a;
  return gcd(b, a % b);
};
LL lcm(LL a, LL b) {
  LL g = gcd(a, b);
  return a / g * b;
};
#define ALL(qpqpq) (qpqpq).begin(), (qpqpq).end()
#define UNIQUE(wpwpw)                                                          \
  sort(ALL((wpwpw)));                                                          \
  (wpwpw).erase(unique(ALL((wpwpw))), (wpwpw).end())
#define LOWER(epepe) transform(ALL((epepe)), (epepe).begin(), TL<char>)
#define UPPER(rprpr) transform(ALL((rprpr)), (rprpr).begin(), TU<char>)
#define FOR(i, tptpt, ypypy) for (LL i = (tptpt); i < (ypypy); i++)
#define REP(i, upupu) FOR(i, 0, upupu)
#define INIT                                                                   \
  std::ios::sync_with_stdio(false);                                            \
  std::cin.tie(0)
#pragma warning(disable : 4996)

int V, E;
struct edge {
  LL to, cost;
};
int start;
LL d[100100]; // 距離
vector<edge> vec[1010];

void dijkstra() {
  for (int i = 0; i < 100100; i++)
    d[i] = HINF<LL>();
  priority_queue<pii, std::vector<pii>, std::greater<pii>> pq;
  d[start] = 0;
  pq.push(make_pair(d[start], start)); // cost,to
  while (!pq.empty()) {
    pii p = pq.top();
    pq.pop();
    int i = p.second;
    if (d[i] < p.first)
      continue;
    for (int k = 0; k < vec[i].size(); k++) {
      edge e = vec[i][k];
      if (d[e.to] <= d[i] + e.cost)
        continue;
      d[e.to] = d[i] + e.cost;
      pq.push(make_pair(d[e.to], e.to));
    }
  }
}

int main() {
  cin >> V;
  REP(i, V) {
    int u;
    cin >> u;
    int num;
    cin >> num;
    REP(j, num) {
      int v, c;
      cin >> v >> c;
      vec[u].emplace_back(edge{v, c});
    }
  }
  dijkstra();
  REP(i, V) { cout << i << " " << d[i] << endl; }
}


Fixed submission:
#include "bits/stdc++.h"
using namespace std;
using LL = long long;
using ULL = unsigned long long;
const double PI = acos(-1);
template <class T> constexpr T INF() { return ::std::numeric_limits<T>::max(); }
template <class T> constexpr T HINF() { return INF<T>() / 2; }
template <typename T_char> T_char TL(T_char cX) { return tolower(cX); };
template <typename T_char> T_char TU(T_char cX) { return toupper(cX); };
typedef pair<LL, LL> pii;
const int vy[] = {-1, -1, -1, 0, 1, 1, 1, 0},
          vx[] = {-1, 0, 1, 1, 1, 0, -1, -1};
const int dx[4] = {0, 1, 0, -1}, dy[4] = {1, 0, -1, 0};
int popcnt(unsigned long long n) {
  int cnt = 0;
  for (int i = 0; i < 64; i++)
    if ((n >> i) & 1)
      cnt++;
  return cnt;
}
int d_sum(LL n) {
  int ret = 0;
  while (n > 0) {
    ret += n % 10;
    n /= 10;
  }
  return ret;
}
int d_cnt(LL n) {
  int ret = 0;
  while (n > 0) {
    ret++;
    n /= 10;
  }
  return ret;
}
LL gcd(LL a, LL b) {
  if (b == 0)
    return a;
  return gcd(b, a % b);
};
LL lcm(LL a, LL b) {
  LL g = gcd(a, b);
  return a / g * b;
};
#define ALL(qpqpq) (qpqpq).begin(), (qpqpq).end()
#define UNIQUE(wpwpw)                                                          \
  sort(ALL((wpwpw)));                                                          \
  (wpwpw).erase(unique(ALL((wpwpw))), (wpwpw).end())
#define LOWER(epepe) transform(ALL((epepe)), (epepe).begin(), TL<char>)
#define UPPER(rprpr) transform(ALL((rprpr)), (rprpr).begin(), TU<char>)
#define FOR(i, tptpt, ypypy) for (LL i = (tptpt); i < (ypypy); i++)
#define REP(i, upupu) FOR(i, 0, upupu)
#define INIT                                                                   \
  std::ios::sync_with_stdio(false);                                            \
  std::cin.tie(0)
#pragma warning(disable : 4996)

int V, E;
struct edge {
  LL to, cost;
};
int start;
LL d[100100]; // 距離
vector<edge> vec[101010];

void dijkstra() {
  for (int i = 0; i < 100100; i++)
    d[i] = HINF<LL>();
  priority_queue<pii, std::vector<pii>, std::greater<pii>> pq;
  d[start] = 0;
  pq.push(make_pair(d[start], start)); // cost,to
  while (!pq.empty()) {
    pii p = pq.top();
    pq.pop();
    int i = p.second;
    if (d[i] < p.first)
      continue;
    for (int k = 0; k < vec[i].size(); k++) {
      edge e = vec[i][k];
      if (d[e.to] <= d[i] + e.cost)
        continue;
      d[e.to] = d[i] + e.cost;
      pq.push(make_pair(d[e.to], e.to));
    }
  }
}

int main() {
  cin >> V;
  REP(i, V) {
    int u;
    cin >> u;
    int num;
    cin >> num;
    REP(j, num) {
      int v, c;
      cin >> v >> c;
      vec[u].emplace_back(edge{v, c});
    }
  }
  dijkstra();
  REP(i, V) { cout << i << " " << d[i] << endl; }
}