Problem p00449 (C++) — buggy submission, verdict: Time Limit Exceeded

#define _USE_MATH_DEFINES
#include "bits/stdc++.h"
using namespace std;

// #define int long long
#define DBG 1
#define dump(o)                                                                \\
  if (DBG) {                                                                   \\
    cerr << #o << " " << o << endl;                                            \\
  }
#define dumpc(o)                                                               \\
  if (DBG) {                                                                   \\
    cerr << #o;                                                                \\
    for (auto &e : (o))                                                        \\
      cerr << " " << e;                                                        \\
    cerr << endl;                                                              \\
  }
#define rep(i, a, b) for (int i = (a); i < (b); i++)
#define rrep(i, a, b) for (int i = (b)-1; i >= (a); i--)
#define each(it, c) for (auto it = (c).begin(); it != (c).end(); it++)
#define all(c) c.begin(), c.end()
const int INF =
    sizeof(int) == sizeof(long long) ? 0x3f3f3f3f3f3f3f3fLL : 0x3f3f3f3f;
const int MOD = (int)(1e9 + 7);

signed main() {
  int n;
  while (cin >> n, n) {
    vector<vector<int>> v(n, vector<int>(n, INF));
    rep(i, 0, n) v[i][i] = 0;
    int k;
    cin >> k;
    bool f = false;
    rep(i, 0, k) {
      int x;
      cin >> x;
      if (x == 0) {
        if (!f) {
          rep(j, 0, n) {
            rep(l, 0, n) {
              rep(h, 0, n) { v[l][h] = min(v[l][h], v[l][j] + v[j][h]); }
            }
          }
          f = true;
        }

        int a, b;
        cin >> a >> b;
        a--;
        b--;
        cout << ((v[a][b] == INF) ? -1 : v[a][b]) << endl;
      } else {
        int c, d, e;
        cin >> c >> d >> e;
        c--;
        d--;
        v[c][d] = v[d][c] = min(v[c][d], e);
        f = false;
      }
    }
  }
  return 0;
}

Error: TLE

Fixed submission:

#define _USE_MATH_DEFINES
#include "bits/stdc++.h"
using namespace std;

// #define int long long
#define DBG 1
#define dump(o)                                                                \\
  if (DBG) {                                                                   \\
    cerr << #o << " " << o << endl;                                            \\
  }
#define dumpc(o)                                                               \\
  if (DBG) {                                                                   \\
    cerr << #o;                                                                \\
    for (auto &e : (o))                                                        \\
      cerr << " " << e;                                                        \\
    cerr << endl;                                                              \\
  }
#define rep(i, a, b) for (int i = (a); i < (b); i++)
#define rrep(i, a, b) for (int i = (b)-1; i >= (a); i--)
#define each(it, c) for (auto it = (c).begin(); it != (c).end(); it++)
#define all(c) c.begin(), c.end()
const int INF =
    sizeof(int) == sizeof(long long) ? 0x3f3f3f3f3f3f3f3fLL : 0x3f3f3f3f;
const int MOD = (int)(1e9 + 7);

signed main() {
  int n;
  while (cin >> n, n) {
    vector<vector<int>> v(n, vector<int>(n, INF));
    rep(i, 0, n) v[i][i] = 0;
    int k;
    cin >> k;
    rep(i, 0, k) {
      int x;
      cin >> x;
      if (x == 0) {
        rep(j, 0, n) {
          rep(l, 0, n) {
            rep(h, 0, n) { v[l][h] = min(v[l][h], v[l][j] + v[j][h]); }
          }
        }
        int a, b;
        cin >> a >> b;
        a--;
        b--;
        cout << ((v[a][b] == INF) ? -1 : v[a][b]) << endl;
      } else {
        int c, d, e;
        cin >> c >> d >> e;
        c--;
        d--;
        v[c][d] = v[d][c] = min(v[c][d], e);
      }
    }
  }
  return 0;
}