Problem p03837 (C++)

Buggy submission (status: Runtime Error):
#include <algorithm>
#include <cmath>
#include <complex> // complex<double> a(1.2 , 2.3);// real(): 1.2, imag()2.3
#include <cstring>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <vector>
using namespace std;

#define MOD 1000000007
#define ll long long
#define ld long double
#define FOR(i, a, b) for (ll i = (ll)a; i < (ll)b; i++)
#define rep(i, n) FOR(i, 0, n)
#define pb push_back
#define mp make_pair
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define rmsame(a) sort(all(a)), a.erase(unique(all(a)), a.end())
#define rmvector(a, b)                                                         \
  rep(i, a.size()) rep(j, b.size()) if (a[i] == b[j]) {                        \
    a.erase(a.begin() + i);                                                    \
    i--;                                                                       \
    break;                                                                     \
  }
#define pq_pair_tB                                                             \
  priority_queue<pair<ll, ll>, vector<pair<ll, ll>>, greater<pair<ll, ll>>>
#define pq_pair_ts priority_queue<pair<ll, ll>> // 第二成分の大きさが関係ない
template <typename X> bool exist(vector<X> vec, X item) {
  return find(all(vec), item) != vec.end();
}
ll gcd(ll a, ll b) {
  if (b == 0)
    return a;
  return gcd(b, a % b);
}
ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }

ll E[100][100];

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);

  rep(i, 100) rep(j, 100) E[i][j] = 100000;

  ll N, M;
  cin >> N >> M;
  vector<pair<pair<ll, ll>, ll>> abc;

  rep(i, M) {
    ll a, b, c;
    cin >> a >> b >> c;
    a--;
    b--;
    E[a][b] = c;
    E[b][c] = c;

    abc.pb(mp(mp(a, b), c));
  }

  rep(k, N) rep(i, N) rep(j, N) E[i][j] = min(E[i][j], E[i][k] + E[k][j]);

  ll ans = 0;
  rep(i, abc.size()) {
    ll a = abc[i].first.first;
    ll b = abc[i].first.second;
    ll c = abc[i].second;

    if (E[a][b] != c) {
      ans++;
    }
  }

  cout << ans << endl;

  // cout << fixed << setprecision(16) << ans << endl;
  return 0;
}


Fixed submission:
#include <algorithm>
#include <cmath>
#include <complex> // complex<double> a(1.2 , 2.3);// real(): 1.2, imag()2.3
#include <cstring>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <vector>
using namespace std;

#define MOD 1000000007
#define ll long long
#define ld long double
#define FOR(i, a, b) for (ll i = (ll)a; i < (ll)b; i++)
#define rep(i, n) FOR(i, 0, n)
#define pb push_back
#define mp make_pair
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define rmsame(a) sort(all(a)), a.erase(unique(all(a)), a.end())
#define rmvector(a, b)                                                         \
  rep(i, a.size()) rep(j, b.size()) if (a[i] == b[j]) {                        \
    a.erase(a.begin() + i);                                                    \
    i--;                                                                       \
    break;                                                                     \
  }
#define pq_pair_tB                                                             \
  priority_queue<pair<ll, ll>, vector<pair<ll, ll>>, greater<pair<ll, ll>>>
#define pq_pair_ts priority_queue<pair<ll, ll>> // 第二成分の大きさが関係ない
template <typename X> bool exist(vector<X> vec, X item) {
  return find(all(vec), item) != vec.end();
}
ll gcd(ll a, ll b) {
  if (b == 0)
    return a;
  return gcd(b, a % b);
}
ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }

ll E[100][100];

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);

  rep(i, 100) rep(j, 100) E[i][j] = 100000;

  ll N, M;
  cin >> N >> M;
  vector<pair<pair<ll, ll>, ll>> abc;

  rep(i, M) {
    ll a, b, c;
    cin >> a >> b >> c;
    a--;
    b--;
    E[a][b] = c;
    E[b][a] = c;

    abc.pb(mp(mp(a, b), c));
  }

  rep(k, N) rep(i, N) rep(j, N) E[i][j] = min(E[i][j], E[i][k] + E[k][j]);

  ll ans = 0;
  rep(i, abc.size()) {
    ll a = abc[i].first.first;
    ll b = abc[i].first.second;
    ll c = abc[i].second;

    if (E[a][b] != c) {
      ans++;
    }
  }

  cout << ans << endl;

  // cout << fixed << setprecision(16) << ans << endl;
  return 0;
}