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

#include <algorithm>
#include <array>
#include <bitset>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdlib>
#include <deque>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <limits>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <vector>
// #include "utiltime.hpp"

using namespace std;

typedef long long int ll;
typedef vector<int> vi;
typedef vector<vector<int>> vvi;
typedef pair<int, int> P;
typedef pair<ll, ll> Pll;
typedef vector<ll> vll;
typedef vector<vector<ll>> vvll;
typedef complex<double> cdouble;

const int INFL = (int)1e9;
const ll INFLL = (ll)1e18;
const double INFD = numeric_limits<double>::infinity();
const double PI = 3.14159265358979323846;
#define Loop(i, n) for (int i = 0; i < (int)n; i++)
#define Loopll(i, n) for (ll i = 0; i < (ll)n; i++)
#define Loop1(i, n) for (int i = 1; i <= (int)n; i++)
#define Loopll1(i, n) for (ll i = 1; i <= (ll)n; i++)
#define Loopr(i, n) for (int i = (int)n - 1; i >= 0; i--)
#define Looprll(i, n) for (ll i = (ll)n - 1; i >= 0; i--)
#define Loopr1(i, n) for (int i = (int)n; i >= 1; i--)
#define Looprll1(i, n) for (ll i = (ll)n; i >= 1; i--)
#define Foreach(buf, container) for (auto buf : container)
#define Loopdiag(i, j, h, w, sum)                                              \\
  for (int i = ((sum) >= h ? h - 1 : (sum)), j = (sum)-i; i >= 0 && j < w;     \\
       i--, j++)
#define Loopdiagr(i, j, h, w, sum)                                             \\
  for (int j = ((sum) >= w ? w - 1 : (sum)), i = (sum)-j; j >= 0 && i < h;     \\
       j--, i++)
#define Loopdiagsym(i, j, h, w, gap)                                           \\
  for (int i = ((gap) >= 0 ? (gap) : 0), j = i - (gap); i < (h) && j < (w);    \\
       i++, j++)
#define Loopdiagsymr(i, j, h, w, gap)                                          \\
  for (int i = ((gap) > (h) - (w)-1 ? (h)-1 : (w)-1 + (gap)), j = i - (gap);   \\
       i >= 0 && j >= 0; i--, j--)
#define Loopitr(itr, container)                                                \\
  for (auto itr = container.begin(); itr != container.end(); itr++)
#define printv(vector)                                                         \\
  Loop(extra_i, vector.size()) { cout << vector[extra_i] << " "; }             \\
  cout << endl;
#define printmx(matrix)                                                        \\
  Loop(extra_i, matrix.size()) {                                               \\
    Loop(extra_j, matrix[extra_i].size()) {                                    \\
      cout << matrix[extra_i][extra_j] << " ";                                 \\
    }                                                                          \\
    cout << endl;                                                              \\
  }
#define quickio()                                                              \\
  ios::sync_with_stdio(false);                                                 \\
  cin.tie(0);
#define readfile(filename)                                                     \\
  ifstream in(filename);                                                       \\
  cin.rdbuf(in.rdbuf());
#define bitmanip(m, val) static_cast<bitset<(int)m>>(val)
bool nearlyeq(double x, double y) { return abs(x - y) < 1e-9; }
bool inrange(int x, int t) { return x >= 0 && x < t; }
ll rndf(double x) { return (ll)(x + (x >= 0 ? 0.5 : -0.5)); }
ll floorsqrt(double x) {
  ll m = (ll)sqrt(x);
  return m + (m * m <= (ll)(x) ? 0 : -1);
}
ll ceilsqrt(double x) {
  ll m = (ll)sqrt(x);
  return m + ((ll)x <= m * m ? 0 : 1);
}
ll rnddiv(ll a, ll b) { return (a / b + (a % b * 2 >= b ? 1 : 0)); }
ll ceildiv(ll a, ll b) { return (a / b + (a % b == 0 ? 0 : 1)); }
ll gcd(ll m, ll n) {
  if (n == 0)
    return m;
  else
    return gcd(n, m % n);
}

/*******************************************************/

/*
typedef ll val_t;

struct graph_t {
        int n;           // |V|, index begins with 0
        int m;           // |E|
        vector<P> edges; // E
        vector<val_t> vals; // V
        vector<ll> costs; // cost or distance
        vector<ll> caps;  // capacity
};

class Mincostflow {
private:
        // note: eid of dual_edge is negative
        struct edgedata {
                int eid, from, to;
                ll cap, cost;
                int dual_p;
        };
        struct node {
                int id; bool done; ll d; int from; int from_p; int from_eid;
vector<edgedata> edges;
        };
        struct pq_t {
                int id; ll d;
                bool operator<(const pq_t & another) const {
                        return d != another.d ? d > another.d : id > another.id;
                }
        };
        vector<node> nodes;
        int n, m;
        int source, sink;
        edgedata* empty_edge;
        bool overflow;
public:
        Mincostflow(graph_t G, int s, int t) {
                n = G.n;
                m = G.edges.size();
                nodes.resize(n);
                Loop(i, n) nodes[i] = { i, false, LLONG_MAX, -1, -1, m, {} };
                empty_edge = new edgedata;
                Loop(i, m) {
                        int a = G.edges[i].first;
                        int b = G.edges[i].second;
                        nodes[a].edges.push_back({ i, a, b, G.caps[i],
G.costs[i], (int)nodes[b].edges.size() }); nodes[b].edges.push_back({ i - m, b,
a, 0, -G.costs[i], (int)nodes[a].edges.size() - 1 });
                }
                source = s;
                sink = t;
                overflow = false;
        }
        bool add_flow(ll f) {
                if (overflow) return false;
                while (f > 0) {
                        Loop(i, n) {
                                nodes[i].done = false;
                                nodes[i].from = -1;
                                nodes[i].from_p = -1;
                                nodes[i].from_eid = m;
                                nodes[i].d = LLONG_MAX;
                        }
                        nodes[source].d = 0;
                        priority_queue<pq_t> pq;
                        pq.push({ nodes[source].id, nodes[source].d });
                        while (pq.size()) {
                                int a = pq.top().id; pq.pop();
                                if (nodes[a].done) continue;
                                nodes[a].done = true;
                                Loop(j, nodes[a].edges.size()) {
                                        edgedata e = nodes[a].edges[j];
                                        if (e.cap == 0) continue;
                                        int b = e.to;
                                        if (nodes[b].done) continue;
                                        ll buf = nodes[a].d + e.cost;
                                        if (buf < nodes[b].d) {
                                                nodes[b].d = buf;
                                                nodes[b].from = a;
                                                nodes[b].from_p = j;
                                                nodes[b].from_eid = e.eid;
                                                pq.push({ nodes[b].id,
nodes[b].d });
                                        }
                                }
                        }
                        if (!nodes[sink].done) {
                                overflow = true;
                                return false;
                        }
                        int a = sink;
                        ll df = f;
                        while (a != source) {
                                df = min(df,
nodes[nodes[a].from].edges[nodes[a].from_p].cap); a = nodes[a].from;
                        }
                        a = sink;
                        while (a != source) {
                                nodes[nodes[a].from].edges[nodes[a].from_p].cap
-= df; nodes[a].edges[nodes[nodes[a].from].edges[nodes[a].from_p].dual_p].cap +=
df; a = nodes[a].from;
                        }
                        f -= df;
                }
                return true;
        }
        vll get_eid_flow() {
                vll ret(m, -1);
                if (overflow) return ret;
                Loop(i, n) {
                        Foreach(e, nodes[i].edges) {
                                if (e.eid < 0) ret[e.eid + m] = e.cap;
                        }
                }
                return ret;
        }
        ll get_flow() {
                ll ret = 0;
                if (overflow) return -1;
                Foreach(e, nodes[sink].edges) {
                        if (e.eid < 0) ret += e.cap;
                }
                return ret;
        }
        ll get_cost() {
                ll ret = 0;
                if (overflow) return -1;
                Loop(i, n) {
                        Foreach(e, nodes[i].edges) {
                                if (e.eid < 0) ret -= e.cap * e.cost;
                        }
                }
                return ret;
        }
};

int main() {
        graph_t G; cin >> G.n; cin >> G.m;
        ll f; cin >> f;
        Loop(i, G.m) {
                int s, t; cin >> s >> t;
                ll cap, cost; cin >> cap >> cost;
                G.edges.push_back({ s, t });
                G.caps.push_back(cap);
                G.costs.push_back(cost);
        }
        Mincostflow mcf(G, 0, G.n - 1);
        if (mcf.add_flow(f)) cout << mcf.get_cost() << endl;
        else cout << -1 << endl;
}

*/

typedef ll val_t;

struct graph_t {
  int n;              // |V|, index begins with 0
  int m;              // |E|
  vector<P> edges;    // E
  vector<val_t> vals; // V
  vector<ll> costs;   // cost or distance
  vector<ll> caps;    // capacity
};

class Maxflow {
private:
  // note: eid of dual_edge is negative
  struct edge {
    int eid, from, to;
    ll cap;
  };
  struct node {
    int id;
    bool done;
    vector<int> to_eids;
  };
  int dual_eid(int eid) {
    if (eid < m)
      return eid + m;
    else
      return eid - m;
  }
  ll dfs(int a, ll f) {
    if (a == sink)
      return f;
    nodes[a].done = true;
    Foreach(eid, nodes[a].to_eids) {
      int b = edges[eid].to;
      if (!nodes[b].done && edges[eid].cap > 0) {
        ll df = dfs(b, min(f, edges[eid].cap));
        if (df > 0) {
          edges[eid].cap -= df;
          edges[dual_eid(eid)].cap += df;
          return df;
        }
      }
    }
    return 0;
  }
  vector<node> nodes;
  vector<edge> edges;
  int n, m;
  int source, sink;

public:
  Maxflow(graph_t G, int s, int t) {
    n = G.n;
    m = G.edges.size();
    nodes.resize(n);
    edges.resize(m * 2);
    Loop(i, n) nodes[i] = {i, false, {}};
    Loop(i, m) {
      int a = G.edges[i].first;
      int b = G.edges[i].second;
      nodes[a].to_eids.push_back(i);
      nodes[b].to_eids.push_back(i + m);
      edges[i] = {i, a, b, G.caps[i]};
      edges[i + m] = {i + m, b, a, 0};
    }
    source = s;
    sink = t;
    while (dfs(source, LLONG_MAX)) {
      Loop(i, n) nodes[i].done = false;
    }
    return;
  }
  vll get_eid_flow() {
    vll ret(m);
    Loop(i, edges.size()) { ret[i] = edges[i + m].cap; }
    return ret;
  }
  ll get_maxflow() {
    ll ret = 0;
    Foreach(eid, nodes[sink].to_eids) {
      if (eid >= m)
        ret += edges[eid].cap;
    }
    return ret;
  }
};

int main() {
  graph_t G;
  cin >> G.n >> G.m;
  Loop(i, G.m) {
    int s, t;
    cin >> s >> t;
    ll c;
    cin >> c;
    G.edges.push_back({s, t});
    G.caps.push_back(c);
  }
  Maxflow mf(G, 0, G.n - 1);
  cout << mf.get_maxflow() << endl;
}


Error: 0

Fixed submission:

#include <algorithm>
#include <array>
#include <bitset>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdlib>
#include <deque>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <limits>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <vector>
// #include "utiltime.hpp"

using namespace std;

typedef long long int ll;
typedef vector<int> vi;
typedef vector<vector<int>> vvi;
typedef pair<int, int> P;
typedef pair<ll, ll> Pll;
typedef vector<ll> vll;
typedef vector<vector<ll>> vvll;
typedef complex<double> cdouble;

const int INFL = (int)1e9;
const ll INFLL = (ll)1e18;
const double INFD = numeric_limits<double>::infinity();
const double PI = 3.14159265358979323846;
#define Loop(i, n) for (int i = 0; i < (int)n; i++)
#define Loopll(i, n) for (ll i = 0; i < (ll)n; i++)
#define Loop1(i, n) for (int i = 1; i <= (int)n; i++)
#define Loopll1(i, n) for (ll i = 1; i <= (ll)n; i++)
#define Loopr(i, n) for (int i = (int)n - 1; i >= 0; i--)
#define Looprll(i, n) for (ll i = (ll)n - 1; i >= 0; i--)
#define Loopr1(i, n) for (int i = (int)n; i >= 1; i--)
#define Looprll1(i, n) for (ll i = (ll)n; i >= 1; i--)
#define Foreach(buf, container) for (auto buf : container)
#define Loopdiag(i, j, h, w, sum)                                              \\
  for (int i = ((sum) >= h ? h - 1 : (sum)), j = (sum)-i; i >= 0 && j < w;     \\
       i--, j++)
#define Loopdiagr(i, j, h, w, sum)                                             \\
  for (int j = ((sum) >= w ? w - 1 : (sum)), i = (sum)-j; j >= 0 && i < h;     \\
       j--, i++)
#define Loopdiagsym(i, j, h, w, gap)                                           \\
  for (int i = ((gap) >= 0 ? (gap) : 0), j = i - (gap); i < (h) && j < (w);    \\
       i++, j++)
#define Loopdiagsymr(i, j, h, w, gap)                                          \\
  for (int i = ((gap) > (h) - (w)-1 ? (h)-1 : (w)-1 + (gap)), j = i - (gap);   \\
       i >= 0 && j >= 0; i--, j--)
#define Loopitr(itr, container)                                                \\
  for (auto itr = container.begin(); itr != container.end(); itr++)
#define printv(vector)                                                         \\
  Loop(extra_i, vector.size()) { cout << vector[extra_i] << " "; }             \\
  cout << endl;
#define printmx(matrix)                                                        \\
  Loop(extra_i, matrix.size()) {                                               \\
    Loop(extra_j, matrix[extra_i].size()) {                                    \\
      cout << matrix[extra_i][extra_j] << " ";                                 \\
    }                                                                          \\
    cout << endl;                                                              \\
  }
#define quickio()                                                              \\
  ios::sync_with_stdio(false);                                                 \\
  cin.tie(0);
#define readfile(filename)                                                     \\
  ifstream in(filename);                                                       \\
  cin.rdbuf(in.rdbuf());
#define bitmanip(m, val) static_cast<bitset<(int)m>>(val)
bool nearlyeq(double x, double y) { return abs(x - y) < 1e-9; }
bool inrange(int x, int t) { return x >= 0 && x < t; }
ll rndf(double x) { return (ll)(x + (x >= 0 ? 0.5 : -0.5)); }
ll floorsqrt(double x) {
  ll m = (ll)sqrt(x);
  return m + (m * m <= (ll)(x) ? 0 : -1);
}
ll ceilsqrt(double x) {
  ll m = (ll)sqrt(x);
  return m + ((ll)x <= m * m ? 0 : 1);
}
ll rnddiv(ll a, ll b) { return (a / b + (a % b * 2 >= b ? 1 : 0)); }
ll ceildiv(ll a, ll b) { return (a / b + (a % b == 0 ? 0 : 1)); }
ll gcd(ll m, ll n) {
  if (n == 0)
    return m;
  else
    return gcd(n, m % n);
}

/*******************************************************/

/*
typedef ll val_t;

struct graph_t {
        int n;           // |V|, index begins with 0
        int m;           // |E|
        vector<P> edges; // E
        vector<val_t> vals; // V
        vector<ll> costs; // cost or distance
        vector<ll> caps;  // capacity
};

class Mincostflow {
private:
        // note: eid of dual_edge is negative
        struct edgedata {
                int eid, from, to;
                ll cap, cost;
                int dual_p;
        };
        struct node {
                int id; bool done; ll d; int from; int from_p; int from_eid;
vector<edgedata> edges;
        };
        struct pq_t {
                int id; ll d;
                bool operator<(const pq_t & another) const {
                        return d != another.d ? d > another.d : id > another.id;
                }
        };
        vector<node> nodes;
        int n, m;
        int source, sink;
        edgedata* empty_edge;
        bool overflow;
public:
        Mincostflow(graph_t G, int s, int t) {
                n = G.n;
                m = G.edges.size();
                nodes.resize(n);
                Loop(i, n) nodes[i] = { i, false, LLONG_MAX, -1, -1, m, {} };
                empty_edge = new edgedata;
                Loop(i, m) {
                        int a = G.edges[i].first;
                        int b = G.edges[i].second;
                        nodes[a].edges.push_back({ i, a, b, G.caps[i],
G.costs[i], (int)nodes[b].edges.size() }); nodes[b].edges.push_back({ i - m, b,
a, 0, -G.costs[i], (int)nodes[a].edges.size() - 1 });
                }
                source = s;
                sink = t;
                overflow = false;
        }
        bool add_flow(ll f) {
                if (overflow) return false;
                while (f > 0) {
                        Loop(i, n) {
                                nodes[i].done = false;
                                nodes[i].from = -1;
                                nodes[i].from_p = -1;
                                nodes[i].from_eid = m;
                                nodes[i].d = LLONG_MAX;
                        }
                        nodes[source].d = 0;
                        priority_queue<pq_t> pq;
                        pq.push({ nodes[source].id, nodes[source].d });
                        while (pq.size()) {
                                int a = pq.top().id; pq.pop();
                                if (nodes[a].done) continue;
                                nodes[a].done = true;
                                Loop(j, nodes[a].edges.size()) {
                                        edgedata e = nodes[a].edges[j];
                                        if (e.cap == 0) continue;
                                        int b = e.to;
                                        if (nodes[b].done) continue;
                                        ll buf = nodes[a].d + e.cost;
                                        if (buf < nodes[b].d) {
                                                nodes[b].d = buf;
                                                nodes[b].from = a;
                                                nodes[b].from_p = j;
                                                nodes[b].from_eid = e.eid;
                                                pq.push({ nodes[b].id,
nodes[b].d });
                                        }
                                }
                        }
                        if (!nodes[sink].done) {
                                overflow = true;
                                return false;
                        }
                        int a = sink;
                        ll df = f;
                        while (a != source) {
                                df = min(df,
nodes[nodes[a].from].edges[nodes[a].from_p].cap); a = nodes[a].from;
                        }
                        a = sink;
                        while (a != source) {
                                nodes[nodes[a].from].edges[nodes[a].from_p].cap
-= df; nodes[a].edges[nodes[nodes[a].from].edges[nodes[a].from_p].dual_p].cap +=
df; a = nodes[a].from;
                        }
                        f -= df;
                }
                return true;
        }
        vll get_eid_flow() {
                vll ret(m, -1);
                if (overflow) return ret;
                Loop(i, n) {
                        Foreach(e, nodes[i].edges) {
                                if (e.eid < 0) ret[e.eid + m] = e.cap;
                        }
                }
                return ret;
        }
        ll get_flow() {
                ll ret = 0;
                if (overflow) return -1;
                Foreach(e, nodes[sink].edges) {
                        if (e.eid < 0) ret += e.cap;
                }
                return ret;
        }
        ll get_cost() {
                ll ret = 0;
                if (overflow) return -1;
                Loop(i, n) {
                        Foreach(e, nodes[i].edges) {
                                if (e.eid < 0) ret -= e.cap * e.cost;
                        }
                }
                return ret;
        }
};

int main() {
        graph_t G; cin >> G.n; cin >> G.m;
        ll f; cin >> f;
        Loop(i, G.m) {
                int s, t; cin >> s >> t;
                ll cap, cost; cin >> cap >> cost;
                G.edges.push_back({ s, t });
                G.caps.push_back(cap);
                G.costs.push_back(cost);
        }
        Mincostflow mcf(G, 0, G.n - 1);
        if (mcf.add_flow(f)) cout << mcf.get_cost() << endl;
        else cout << -1 << endl;
}

*/

typedef ll val_t;

struct graph_t {
  int n;              // |V|, index begins with 0
  int m;              // |E|
  vector<P> edges;    // E
  vector<val_t> vals; // V
  vector<ll> costs;   // cost or distance
  vector<ll> caps;    // capacity
};

class Maxflow {
private:
  // note: eid of dual_edge is negative
  struct edge {
    int eid, from, to;
    ll cap;
  };
  struct node {
    int id;
    bool done;
    vector<int> to_eids;
  };
  ll dfs(int a, ll f) {
    if (a == sink)
      return f;
    nodes[a].done = true;
    Foreach(eid, nodes[a].to_eids) {
      int b = edges[eid].to;
      if (!nodes[b].done && edges[eid].cap > 0) {
        ll df = dfs(b, min(f, edges[eid].cap));
        if (df > 0) {
          edges[eid].cap -= df;
          edges[eid + m].cap += df;
          return df;
        }
      }
    }
    return 0;
  }
  vector<node> nodes;
  vector<edge> edges;
  int n, m;
  int source, sink;

public:
  Maxflow(graph_t G, int s, int t) {
    n = G.n;
    m = G.edges.size();
    nodes.resize(n);
    edges.resize(m * 2);
    Loop(i, n) nodes[i] = {i, false, {}};
    Loop(i, m) {
      int a = G.edges[i].first;
      int b = G.edges[i].second;
      nodes[a].to_eids.push_back(i);
      nodes[b].to_eids.push_back(i + m);
      edges[i] = {i, a, b, G.caps[i]};
      edges[i + m] = {i + m, b, a, 0};
    }
    source = s;
    sink = t;
    while (dfs(source, LLONG_MAX)) {
      Loop(i, n) nodes[i].done = false;
    }
    return;
  }
  vll get_eid_flow() {
    vll ret(m);
    Loop(i, edges.size()) { ret[i] = edges[i + m].cap; }
    return ret;
  }
  ll get_maxflow() {
    ll ret = 0;
    Foreach(eid, nodes[sink].to_eids) {
      if (eid >= m)
        ret += edges[eid].cap;
    }
    return ret;
  }
};

int main() {
  graph_t G;
  cin >> G.n >> G.m;
  Loop(i, G.m) {
    int s, t;
    cin >> s >> t;
    ll c;
    cin >> c;
    G.edges.push_back({s, t});
    G.caps.push_back(c);
  }
  Maxflow mf(G, 0, G.n - 1);
  cout << mf.get_maxflow() << endl;
}