Problem p02376 (C++) — buggy submission, verdict: Runtime Error

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

//?????????
#pragma region MACRO
#define putans(x)                                                              \\
  std::cerr << "[ answer ]: ";                                                 \\
  cout << (x) << endl
#define dputans(x)                                                             \\
  std::cerr << "[ answer ]: ";                                                 \\
  cout << setprecision(27) << (double)(x) << endl
#define REP(i, a, n) for (int i = (a); i < (int)(n); i++)
#define RREP(i, a, n) for (int i = (int)(n - 1); i >= a; i--)
#define rep(i, n) REP(i, 0, n)
#define rrep(i, n) RREP(i, 0, n)
#define all(a) begin((a)), end((a))
#define mp make_pair
#define exist(container, n) ((container).find((n)) != (container).end())
#define equals(a, b) (fabs((a) - (b)) < EPS)
#ifdef _DEBUG //???????????????????????????????????????????????????
std::ifstream ifs("data.txt");
#define put ifs >>
#else //?????£????????????????????§?????????????????????
#define put cin >>
#endif
#pragma endregion
//???????????°??????????????´
#pragma region CODING_SUPPORT
#ifdef _DEBUG
#define dbg(var0)                                                              \\
  { std::cerr << (#var0) << "=" << (var0) << endl; }
#define dbg2(var0, var1)                                                       \\
  {                                                                            \\
    std::cerr << (#var0) << "=" << (var0) << ", ";                             \\
    dbg(var1);                                                                 \\
  }
#define dbg3(var0, var1, var2)                                                 \\
  {                                                                            \\
    std::cerr << (#var0) << "=" << (var0) << ", ";                             \\
    dbg2(var1, var2);                                                          \\
  }
#define dbgArray(a, n)                                                         \\
  {                                                                            \\
    std::cerr << (#a) << "=";                                                  \\
    rep(i, n) { std::cerr << (a[i]) << ","; }                                  \\
    cerr << endl;                                                              \\
  }
#else
#define dbg(var0)                                                              \\
  {}
#define dbg2(var0, var1)                                                       \\
  {}
#define dbg3(var0, var1, var2)                                                 \\
  {}
#define dbgArray(a, n)                                                         \\
  {}
#endif
#pragma endregion
// typedef????????????????????????????¶????????????§?????????
#pragma region TYPE_DEF
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<string, string> pss;
typedef pair<int, string> pis;
typedef vector<string> vs;
typedef vector<int> vi;
#pragma endregion
//??????????????°(???????????????????????§??????)
#pragma region CONST_VAL
#define PI (2 * acos(0.0))
#define EPS (1e-10)
#define MOD (ll)(1e9 + 7)
#define INF (ll)(2 * 1e9)
#pragma endregion

struct edge {
  int to, cap, rev;
};

static const int MAX_V = 10000;
int V;
vector<edge> G[MAX_V];
int level[MAX_V];
int iter[MAX_V];

void addEdge(int from, int to, int cap) {
  G[from].push_back((edge{to, cap, (int)G[to].size()}));
  G[to].push_back((edge{from, 0, (int)G[from].size() - 1}));
}

void dinicBFS(int s) {
  fill(level, level + V, -1);
  queue<int> que;
  level[s] = 0;
  que.push(s);
  while (!que.empty()) {
    int v = que.front();
    que.pop();
    rep(i, G[v].size()) {
      edge &e = G[v][i];
      if (e.cap > 0 && level[e.to] < 0) {
        level[e.to] = level[v] + 1;
        que.push(e.to);
      }
    }
  }
}

int dinicDFS(int v, int t, int f) {
  if (v == t)
    return f;
  for (int &i = iter[v]; i < G[v].size(); i++) {
    edge &e = G[v][i];
    if (e.cap > 0 && level[v] < level[e.to]) {
      int d = dinicDFS(e.to, t, min(f, e.cap));
      if (d > 0) {
        e.cap -= d;
        G[e.to][e.rev].cap += d;
        return d;
      }
    }
  }
  return 0;
}

int maxFlowDinic(int s, int t) {
  int flow = 0;
  for (;;) {
    dinicBFS(s);
    if (level[t] < 0)
      return flow;
    fill(iter, iter + V, 0);
    int f;
    while ((f = dinicDFS(s, t, INF)) > 0) {
      flow += f;
    }
  }
}

int main() {
  int v, e;
  put v >> e;
  V = v;
  rep(i, e) {
    int u, v, c;
    put u >> v >> c;
    addEdge(u, v, c);
  }
  cout << maxFlowDinic(0, v - 1) << endl;

END:
  return 0;
}

// static const int n = 100;
// int d[n][n];

/*
void topologicalSort() {
        auto bfs = [&](int s)->void {
                queue<int> q;
                q.push(s);
                V[s] = true;
                while (!q.empty()) {
                        int u = q.front(); q.pop();
                        rep(i, G[u].size()) {
                                int v = G[u][i];
                                indeg[v]--;
                                if (indeg[v] == 0 && !V[v]) {
                                        q.push();
                                }
                        }
                }
        }
}
rep(i, n) {
        indeg[i] = 0;
}
rep(u, n) {
        rep(i, G[u].size()) {
                int v = G[u][i];
                indeg[v]++;
        }
        rep(i, n) {
                if (indeg[i] == !V[i]) bfs(u);
        }//????????§???????????????
}
}*/

Error: 0

Fixed submission:

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

//?????????
#pragma region MACRO
#define putans(x)                                                              \\
  std::cerr << "[ answer ]: ";                                                 \\
  cout << (x) << endl
#define dputans(x)                                                             \\
  std::cerr << "[ answer ]: ";                                                 \\
  cout << setprecision(27) << (double)(x) << endl
#define REP(i, a, n) for (int i = (a); i < (int)(n); i++)
#define RREP(i, a, n) for (int i = (int)(n - 1); i >= a; i--)
#define rep(i, n) REP(i, 0, n)
#define rrep(i, n) RREP(i, 0, n)
#define all(a) begin((a)), end((a))
#define mp make_pair
#define exist(container, n) ((container).find((n)) != (container).end())
#define equals(a, b) (fabs((a) - (b)) < EPS)
#ifdef _DEBUG //???????????????????????????????????????????????????
std::ifstream ifs("data.txt");
#define put ifs >>
#else //?????£????????????????????§?????????????????????
#define put cin >>
#endif
#pragma endregion
//???????????°??????????????´
#pragma region CODING_SUPPORT
#ifdef _DEBUG
#define dbg(var0)                                                              \\
  { std::cerr << (#var0) << "=" << (var0) << endl; }
#define dbg2(var0, var1)                                                       \\
  {                                                                            \\
    std::cerr << (#var0) << "=" << (var0) << ", ";                             \\
    dbg(var1);                                                                 \\
  }
#define dbg3(var0, var1, var2)                                                 \\
  {                                                                            \\
    std::cerr << (#var0) << "=" << (var0) << ", ";                             \\
    dbg2(var1, var2);                                                          \\
  }
#define dbgArray(a, n)                                                         \\
  {                                                                            \\
    std::cerr << (#a) << "=";                                                  \\
    rep(i, n) { std::cerr << (a[i]) << ","; }                                  \\
    cerr << endl;                                                              \\
  }
#else
#define dbg(var0)                                                              \\
  {}
#define dbg2(var0, var1)                                                       \\
  {}
#define dbg3(var0, var1, var2)                                                 \\
  {}
#define dbgArray(a, n)                                                         \\
  {}
#endif
#pragma endregion
// typedef????????????????????????????¶????????????§?????????
#pragma region TYPE_DEF
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<string, string> pss;
typedef pair<int, string> pis;
typedef vector<string> vs;
typedef vector<int> vi;
#pragma endregion
//??????????????°(???????????????????????§??????)
#pragma region CONST_VAL
#define PI (2 * acos(0.0))
#define EPS (1e-10)
#define MOD (ll)(1e9 + 7)
#define INF (ll)(2 * 1e9)
#pragma endregion

struct edge {
  int to, cap, rev;
};

static const int MAX_V = 10000;
int V;
vector<edge> G[MAX_V];
int level[MAX_V];
int iter[MAX_V];

void addEdge(int from, int to, int cap) {
  G[from].push_back((edge{to, cap, (int)G[to].size()}));
  G[to].push_back((edge{from, 0, (int)G[to].size() - 1}));
}

void dinicBFS(int s) {
  fill(level, level + V, -1);
  queue<int> que;
  level[s] = 0;
  que.push(s);
  while (!que.empty()) {
    int v = que.front();
    que.pop();
    rep(i, G[v].size()) {
      edge &e = G[v][i];
      if (e.cap > 0 && level[e.to] < 0) {
        level[e.to] = level[v] + 1;
        que.push(e.to);
      }
    }
  }
}

int dinicDFS(int v, int t, int f) {
  if (v == t)
    return f;
  for (int &i = iter[v]; i < G[v].size(); i++) {
    edge &e = G[v][i];
    if (e.cap > 0 && level[v] < level[e.to]) {
      int d = dinicDFS(e.to, t, min(f, e.cap));
      if (d > 0) {
        e.cap -= d;
        G[e.to][e.rev].cap += d;
        return d;
      }
    }
  }
  return 0;
}

int maxFlowDinic(int s, int t) {
  int flow = 0;
  for (;;) {
    dinicBFS(s);
    if (level[t] < 0)
      return flow;
    fill(iter, iter + V, 0);
    int f;
    while ((f = dinicDFS(s, t, INF)) > 0)
      flow += f;
  }
}

int main() {
  int v, e;
  put v >> e;
  V = v;
  rep(i, e) {
    int u, v, c;
    put u >> v >> c;
    addEdge(u, v, c);
  }
  cout << maxFlowDinic(0, v - 1) << endl;

END:
  return 0;
}

// static const int n = 100;
// int d[n][n];

/*
void topologicalSort() {
        auto bfs = [&](int s)->void {
                queue<int> q;
                q.push(s);
                V[s] = true;
                while (!q.empty()) {
                        int u = q.front(); q.pop();
                        rep(i, G[u].size()) {
                                int v = G[u][i];
                                indeg[v]--;
                                if (indeg[v] == 0 && !V[v]) {
                                        q.push();
                                }
                        }
                }
        }
}
rep(i, n) {
        indeg[i] = 0;
}
rep(u, n) {
        rep(i, G[u].size()) {
                int v = G[u][i];
                indeg[v]++;
        }
        rep(i, n) {
                if (indeg[i] == !V[i]) bfs(u);
        }//????????§???????????????
}
}*/