Problem p02243 (C++) — buggy submission, verdict: Memory Limit Exceeded

#include <algorithm>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <vector>
using namespace std;

typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef stack<int> SI;
typedef queue<int> QI;
typedef pair<int, int> PII;
typedef long long LL;

#define d(x) cout << #x << " = " << (x) << endl;
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define EMP empty()
#define SZ(a) int((a).size())
#define EACH(i, c)                                                             \\
  for (typeof((c).begin()) i = (c).begin(); i != (c).end(); ++i)
#define REACH(i, c)                                                            \\
  for (typeof((c).rbegin()) i = (c).rbegin(); i != (c).rend(); ++i)
#define EXIST(s, e) ((s).find(e) != (s).end())
#define SORT(c, n) sort(c, c + n)
#define VSORT(c) sort((c).begin(), (c).end())
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define REP(i, n) FOR(i, 0, n)
#define DFOR(i, b, a) for (int i = (b)-1; i >= (a); --i)
#define DREP(i, n) DFOR(i, n, 0)
#define INF 1000000000

const double EPS = 1e-10;
const double PI = acos(-1.0);
////////////////////////////////////////////////
static const int MAX = 10000;
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n;
vector<PII> adj[MAX];
void dijkstra() {
  priority_queue<PII> PQ;
  int color[MAX];
  int d[MAX];
  REP(i, n) {
    d[i] = INF;
    color[i] = WHITE;
  }

  d[0] = 0;
  PQ.push(MP(0, 0));
  color[0] = GRAY;

  while (!PQ.EMP) {
    PII f = PQ.top();
    PQ.pop();
    int u = f.second;
    color[u] = BLACK;

    if (d[u] < f.first * (-1))
      continue;

    REP(j, SZ(adj[u])) {
      int v = adj[u][j].first;
      if (color[v] == BLACK)
        continue;
      if (d[v] > d[u] + adj[u][j].second) {
        d[v] = d[u] + adj[u][j].second;
        PQ.push(MP(d[v] * (-1), v));
        color[v] = GRAY;
      }
    }
  }
  REP(i, n) { cout << i << " " << (d[i] == INF ? -1 : d[i]) << endl; }
}

int main() {
  int k, u, c, v;
  cin >> n;
  REP(i, n) {
    cin >> u >> k;
    REP(j, k) {
      cin >> v >> c;
      adj[u].PB(MP(v, c));
    }
  }

  dijkstra();

  return 0;
}

Error: MLE

Fixed submission:

#include <algorithm>
#include <iostream>
#include <queue>
using namespace std;

static const int MAX = 10000;
static const int INF = (1 << 20);
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n;
vector<pair<int, int>> adj[MAX];
void dijkstra() {
  priority_queue<pair<int, int>> PQ;
  int color[MAX];
  int d[MAX];
  for (int i = 0; i < n; i++) {
    d[i] = INF;
    color[i] = WHITE;
  }

  d[0] = 0;
  PQ.push(make_pair(0, 0));
  color[0] = GRAY;

  while (!PQ.empty()) {
    pair<int, int> f = PQ.top();
    PQ.pop();
    int u = f.second;
    color[u] = BLACK;

    if (d[u] < f.first * (-1))
      continue;

    for (int j = 0; j < adj[u].size(); j++) {
      int v = adj[u][j].first;
      if (color[v] == BLACK)
        continue;
      if (d[v] > d[u] + adj[u][j].second) {
        d[v] = d[u] + adj[u][j].second;
      }
      PQ.push(make_pair(d[v] * (-1), v));
      color[v] = GRAY;
    }
  }
  for (int i = 0; i < n; i++) {
    cout << i << " " << (d[i] == INF ? -1 : d[i]) << endl;
  }
}

int main() {
  int k, u, c, v;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> u >> k;
    for (int j = 0; j < k; j++) {
      cin >> v >> c;
      adj[u].push_back(make_pair(v, c));
    }
  }

  dijkstra();

  return 0;
}