Problem p03995 (C++)

Buggy submission (status: Runtime Error):
#include <bits/stdc++.h>
#include <random>

using namespace std;

typedef unsigned long long ull;
typedef long long ll;
typedef long double ld;
#define int ll
typedef vector<char> vc;
typedef vector<vc> vvc;
typedef vector<vvc> vvvc;
typedef pair<int, int> pii;
typedef pair<pii, pii> piii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<pii> vpi;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<short> vs;
typedef vector<vs> vvs;
typedef vector<vvs> vvvs;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<vvl> vvvl;
typedef vector<ld> vld;
typedef vector<vld> vvld;
typedef vector<vvld> vvvld;
typedef vector<string> vst;
typedef vector<vst> vvst;
typedef pair<ld, ld> pld;

#define inmin(a, b) a = min(a, (b))
#define inmax(a, b) a = max(a, (b))
#define ALL(a) a.begin(), a.end()
#define RALL(a) a.rbegin(), a.rend()
#define sqr(x) ((x) * (x))
#define fori(i, n) for (int i = 0; i < int(n); ++i)
#define SZ(a) ((int)((a).size()))
#define triple(T) tuple<T, T, T>
#define quad(T) tuple<T, T, T, T>
#define watch(x) cerr << (#x) << " = " << (x) << endl;

#ifdef RUS_HOME
#define cerr cout
#else
#define cerr                                                                   \
  if (false)                                                                   \
  cerr
#endif

const double PI = 2 * acos(0.0);
#define rand shittttty_shit
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
mt19937_64 rng_64(chrono::steady_clock::now().time_since_epoch().count());

const string DIGITS = "0123456789";
const string ALPH = "abcdefghijklmnopqrstuvwxyz";

template <class T0, class T1>
inline ostream &operator<<(ostream &out, pair<T0, T1> &a) {
  return out << "{" << a.first << ", " << a.second << "}";
}

template <class T0, class T1>
inline istream &operator>>(istream &in, pair<T0, T1> &a) {
  return in >> a.first >> a.second;
}

template <class T0, class T1, class T2>
inline ostream &operator<<(ostream &out, tuple<T0, T1, T2> &a) {
  return out << "{" << get<0>(a) << ", " << get<1>(a) << ", " << get<2>(a)
             << "}";
}

template <class T0, class T1, class T2, class T3>
inline ostream &operator<<(ostream &out, tuple<T0, T1, T2, T3> &a) {
  return out << "{" << get<0>(a) << ", " << get<1>(a) << ", " << get<2>(a)
             << ", " << get<3>(a) << "}";
}

template <class T> inline ostream &operator<<(ostream &out, vector<T> &a) {
  out << "[";
  fori(i, a.size()) out << a[i]
                        << vector<string>{", ", "]  "}[i + 1 == a.size()];
  return out;
}

void smain();

signed main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
#ifdef RUS_HOME
  freopen("input", "r", stdin);
  // freopen("output.txt", "w", stdout);
  clock_t start = clock();
#endif
  cout << setprecision(12) << fixed;
  smain();
#ifdef RUS_HOME
  cout << "\n\n\n\nTOTAL EXECUTION TIME: "
       << float(clock() - start) / CLOCKS_PER_SEC << endl;
#endif
  return 0;
}

const int MOD = 1e9 + 7, N = 1e5 + 100, M = 18, oo = 1e18;

vpi vec[N][2], g[N], kek;
int chis[N][2];
int lol[N];
bool used[N];
int n, m, k;

void dfs(int v, int zn) {
  used[v] = true;
  kek.push_back({zn, v});
  lol[v] = zn;
  for (auto to : g[v]) {
    int u = to.first, diff = to.second;
    if (used[u]) {
      if (zn - diff != lol[u]) {
        cout << "No";
        exit(0);
      }
    } else {
      dfs(u, zn - diff);
    }
  }
}

void smain() {
  cin >> n >> m >> k;
  for (int i = 1; i <= N; i++) {
    chis[i][0] = chis[i][1] = oo;
  }
  for (int i = 0; i < k; i++) {
    int a, b, c;
    cin >> a >> b >> c;
    inmin(chis[a][0], c);
    inmin(chis[b][1], c);
    vec[a][0].push_back({b, c});
    vec[b][1].push_back({a, c});
  }
  n = max(n, m);
  for (int h = 0; h < 2; h++) {
    for (int i = 1; i <= n; i++) {
      sort(ALL(vec[i][h]));
      for (int j = 1; j < SZ(vec[i][h]); j++) {
        int v = vec[i][h][j - 1].first, u = vec[i][h][j].first,
            diff = vec[i][h][j].second - vec[i][h][j - 1].second;
        g[u].push_back({v, diff});
        g[v].push_back({u, -diff});
      }
    }
    for (int i = 1; i <= n; i++) {
      if (!used[i]) {
        kek.clear();
        dfs(i, 0);
        sort(ALL(kek));
        for (int j = SZ(kek) - 1; j >= 0; j--) {
          kek[j].first -= kek[0].first;
          if (chis[kek[j].second][1 - h] < kek[j].first) {
            cout << "No";
            exit(0);
          }
        }
      }
    }
    for (int i = 1; i <= n; i++) {
      g[i].clear();
      used[i] = false;
    }
  }
  cout << "Yes";
}


Fixed submission:
#include <bits/stdc++.h>
#include <random>

using namespace std;

typedef unsigned long long ull;
typedef long long ll;
typedef long double ld;
#define int ll
typedef vector<char> vc;
typedef vector<vc> vvc;
typedef vector<vvc> vvvc;
typedef pair<int, int> pii;
typedef pair<pii, pii> piii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<pii> vpi;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<short> vs;
typedef vector<vs> vvs;
typedef vector<vvs> vvvs;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<vvl> vvvl;
typedef vector<ld> vld;
typedef vector<vld> vvld;
typedef vector<vvld> vvvld;
typedef vector<string> vst;
typedef vector<vst> vvst;
typedef pair<ld, ld> pld;

#define inmin(a, b) a = min(a, (b))
#define inmax(a, b) a = max(a, (b))
#define ALL(a) a.begin(), a.end()
#define RALL(a) a.rbegin(), a.rend()
#define sqr(x) ((x) * (x))
#define fori(i, n) for (int i = 0; i < int(n); ++i)
#define SZ(a) ((int)((a).size()))
#define triple(T) tuple<T, T, T>
#define quad(T) tuple<T, T, T, T>
#define watch(x) cerr << (#x) << " = " << (x) << endl;

#ifdef RUS_HOME
#define cerr cout
#else
#define cerr                                                                   \
  if (false)                                                                   \
  cerr
#endif

const double PI = 2 * acos(0.0);
#define rand shittttty_shit
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
mt19937_64 rng_64(chrono::steady_clock::now().time_since_epoch().count());

const string DIGITS = "0123456789";
const string ALPH = "abcdefghijklmnopqrstuvwxyz";

template <class T0, class T1>
inline ostream &operator<<(ostream &out, pair<T0, T1> &a) {
  return out << "{" << a.first << ", " << a.second << "}";
}

template <class T0, class T1>
inline istream &operator>>(istream &in, pair<T0, T1> &a) {
  return in >> a.first >> a.second;
}

template <class T0, class T1, class T2>
inline ostream &operator<<(ostream &out, tuple<T0, T1, T2> &a) {
  return out << "{" << get<0>(a) << ", " << get<1>(a) << ", " << get<2>(a)
             << "}";
}

template <class T0, class T1, class T2, class T3>
inline ostream &operator<<(ostream &out, tuple<T0, T1, T2, T3> &a) {
  return out << "{" << get<0>(a) << ", " << get<1>(a) << ", " << get<2>(a)
             << ", " << get<3>(a) << "}";
}

template <class T> inline ostream &operator<<(ostream &out, vector<T> &a) {
  out << "[";
  fori(i, a.size()) out << a[i]
                        << vector<string>{", ", "]  "}[i + 1 == a.size()];
  return out;
}

void smain();

signed main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
#ifdef RUS_HOME
  freopen("input", "r", stdin);
  // freopen("output.txt", "w", stdout);
  clock_t start = clock();
#endif
  cout << setprecision(12) << fixed;
  smain();
#ifdef RUS_HOME
  cout << "\n\n\n\nTOTAL EXECUTION TIME: "
       << float(clock() - start) / CLOCKS_PER_SEC << endl;
#endif
  return 0;
}

const int MOD = 1e9 + 7, N = 1e5 + 100, M = 18, oo = 1e18;

vpi vec[N][2], g[N], kek;
int chis[N][2];
int lol[N];
bool used[N];
int n, m, k;

void dfs(int v, int zn) {
  used[v] = true;
  kek.push_back({zn, v});
  lol[v] = zn;
  for (auto to : g[v]) {
    int u = to.first, diff = to.second;
    if (used[u]) {
      if (zn - diff != lol[u]) {
        cout << "No";
        exit(0);
      }
    } else {
      dfs(u, zn - diff);
    }
  }
}

void smain() {
  cin >> n >> m >> k;
  for (int i = 1; i < N; i++) {
    chis[i][0] = chis[i][1] = oo;
  }
  for (int i = 0; i < k; i++) {
    int a, b, c;
    cin >> a >> b >> c;
    inmin(chis[a][0], c);
    inmin(chis[b][1], c);
    vec[a][0].push_back({b, c});
    vec[b][1].push_back({a, c});
  }
  n = max(n, m);
  for (int h = 0; h < 2; h++) {
    for (int i = 1; i <= n; i++) {
      sort(ALL(vec[i][h]));
      for (int j = 1; j < SZ(vec[i][h]); j++) {
        int v = vec[i][h][j - 1].first, u = vec[i][h][j].first,
            diff = vec[i][h][j].second - vec[i][h][j - 1].second;
        g[u].push_back({v, diff});
        g[v].push_back({u, -diff});
      }
    }
    for (int i = 1; i <= n; i++) {
      if (!used[i]) {
        kek.clear();
        dfs(i, 0);
        sort(ALL(kek));
        for (int j = SZ(kek) - 1; j >= 0; j--) {
          kek[j].first -= kek[0].first;
          if (chis[kek[j].second][1 - h] < kek[j].first) {
            cout << "No";
            exit(0);
          }
        }
      }
    }
    for (int i = 1; i <= n; i++) {
      g[i].clear();
      used[i] = false;
    }
  }
  cout << "Yes";
}