Problem p02949 (C++)

Buggy submission (status: Runtime Error):
// #pragma GCC optimize("Ofast")
// #pragma GCC optimize ("unroll-loops")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

#pragma warning(disable : 4786)
#pragma warning(disable : 4996)
#include <algorithm>
#include <array>
#include <assert.h>
#include <bitset>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <fstream>
#include <functional>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
using namespace std;

#define sim template <class c
#define ris return *this
#define dor > debug &operator<<
#define eni(x)                                                                 \
  sim > typename enable_if<sizeof dud<c>(0) x 1, debug &>::type operator<<(    \
            c i) {
sim > struct rge {
  c b, e;
};
sim > rge<c> range(c i, c j) { return rge<c>{i, j}; }
sim > auto dud(c *x) -> decltype(cerr << *x, 0);
sim > char dud(...);
struct debug {
#ifdef LOCAL
  ~debug() { cerr << endl; }
  template <class c>
  typename enable_if<sizeof dud<c>(0) != 1, debug &>::type operator<<(c i) {
    cerr << boolalpha << i;
    return *this;
  }

  template <class c, int = 0>
  typename enable_if<sizeof dud<c>(0) == 1, debug &>::type operator<<(c i) {
    return *this << range(begin(i), end(i));
  }

  sim, class b dor(pair<b, c> d) {
    ris << "(" << d.first << ", " << d.second << ")";
  }
  sim dor(rge<c> d) {
    *this << "[";
    for (auto it = d.b; it != d.e; ++it)
      *this << ", " + 2 * (it == d.b) << *it;
    ris << "]";
  }
#else
  sim dor(const c &) { ris; }
#endif
};
#define watch(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "

#define MEM(a, b) memset(a, (b), sizeof(a))
#define CLR(a) memset(a, 0, sizeof(a))
#define MAX(a, b) ((a) > (b) ? (a) : (b))
#define MIN(a, b) ((a) < (b) ? (a) : (b))
#define ABS(X) ((X) > 0 ? (X) : (-(X)))
#define S(X) ((X) * (X))
#define SZ(V) (int)V.size()
#define FORN(i, n) for (int i = 0; i < n; i++)
#define FORAB(i, a, b) for (int i = a; i <= b; i++)
#define ALL(V) V.begin(), V.end()
#define IN(A, B, C) ((B) <= (A) && (A) <= (C))
#define AIN(A, B, C) assert(IN(A, B, C))

// typedef int LL;
typedef long long int LL;
// typedef __int128 LLL;
typedef long long LLL;

typedef pair<int, int> PII;
typedef pair<LL, LL> PLL;
typedef pair<double, double> PDD;
typedef vector<int> VI;
typedef vector<LL> VL;
typedef vector<PLL> VPL;
typedef vector<PII> VP;
typedef vector<double> VD;
typedef vector<vector<int>> VVI;
typedef long double ld;

const LL MOD = 998244353;

int vis[2502][2502];
VP V[2502];

int n, m;
vector<tuple<int, int, int>> E;

void dfs(int at, int u) {
  if (vis[u][at])
    return;
  vis[u][at] = 1;
  for (auto &p : V[at]) {
    dfs(p.first, u);
  }
}

int dist[2500];
void solve(int ks) {
  int p;
  scanf("%d %d %d", &n, &m, &p);
  FORN(i, m) {
    int a, b, c;
    scanf("%d %d %d", &a, &b, &c);
    E.push_back(make_tuple(a, b, -(c - p)));
    V[a].push_back({b, c - p});
  }
  for (int i = 1; i <= n; i++)
    dfs(i, i);

  FORAB(i, 1, n) { dist[i] = 1000000000; }
  dist[1] = 0;
  int edit;
  FORAB(i, 1, n) {
    edit = 0;
    for (auto &p : E) {
      if (dist[get<0>(p)] + get<2>(p) < dist[get<1>(p)]) {
        if (vis[1][get<0>(p)] && vis[get<1>(p)][n]) {
          edit = 1;
        }
        dist[get<1>(p)] = dist[get<0>(p)] + get<2>(p);
      }
    }
  }

  LL ans = 0;
  if (edit) {
    ans = -1;
  } else {
    ans = -dist[n];
    if (ans < 0)
      ans = 0;
  }
  printf("%lld\n", ans);
}

int main() {
#ifdef LOCAL
  double start_time = clock();
  freopen("C:\\Home\\ContestCodes\\sample.in", "r", stdin);
  //	freopen("out.out", "w", stdout);
#endif

  if (0) {
    int T;
    scanf("%d", &T);
    // AIN(T, 1, 25);
    for (int ks = 1; ks <= T; ks++) {
      solve(ks);
      fprintf(stderr, "%d done\n", ks);
    }
  } else {
    solve(0);
  }

#ifdef LOCAL
  double end_time = clock();
  fprintf(stderr, "Time = %lf\n", (end_time - start_time) / CLOCKS_PER_SEC);
#endif

  return 0;
}


Fixed submission:
// #pragma GCC optimize("Ofast")
// #pragma GCC optimize ("unroll-loops")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

#pragma warning(disable : 4786)
#pragma warning(disable : 4996)
#include <algorithm>
#include <array>
#include <assert.h>
#include <bitset>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <fstream>
#include <functional>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
using namespace std;

#define sim template <class c
#define ris return *this
#define dor > debug &operator<<
#define eni(x)                                                                 \
  sim > typename enable_if<sizeof dud<c>(0) x 1, debug &>::type operator<<(    \
            c i) {
sim > struct rge {
  c b, e;
};
sim > rge<c> range(c i, c j) { return rge<c>{i, j}; }
sim > auto dud(c *x) -> decltype(cerr << *x, 0);
sim > char dud(...);
struct debug {
#ifdef LOCAL
  ~debug() { cerr << endl; }
  template <class c>
  typename enable_if<sizeof dud<c>(0) != 1, debug &>::type operator<<(c i) {
    cerr << boolalpha << i;
    return *this;
  }

  template <class c, int = 0>
  typename enable_if<sizeof dud<c>(0) == 1, debug &>::type operator<<(c i) {
    return *this << range(begin(i), end(i));
  }

  sim, class b dor(pair<b, c> d) {
    ris << "(" << d.first << ", " << d.second << ")";
  }
  sim dor(rge<c> d) {
    *this << "[";
    for (auto it = d.b; it != d.e; ++it)
      *this << ", " + 2 * (it == d.b) << *it;
    ris << "]";
  }
#else
  sim dor(const c &) { ris; }
#endif
};
#define watch(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "

#define MEM(a, b) memset(a, (b), sizeof(a))
#define CLR(a) memset(a, 0, sizeof(a))
#define MAX(a, b) ((a) > (b) ? (a) : (b))
#define MIN(a, b) ((a) < (b) ? (a) : (b))
#define ABS(X) ((X) > 0 ? (X) : (-(X)))
#define S(X) ((X) * (X))
#define SZ(V) (int)V.size()
#define FORN(i, n) for (int i = 0; i < n; i++)
#define FORAB(i, a, b) for (int i = a; i <= b; i++)
#define ALL(V) V.begin(), V.end()
#define IN(A, B, C) ((B) <= (A) && (A) <= (C))
#define AIN(A, B, C) assert(IN(A, B, C))

// typedef int LL;
typedef long long int LL;
// typedef __int128 LLL;
typedef long long LLL;

typedef pair<int, int> PII;
typedef pair<LL, LL> PLL;
typedef pair<double, double> PDD;
typedef vector<int> VI;
typedef vector<LL> VL;
typedef vector<PLL> VPL;
typedef vector<PII> VP;
typedef vector<double> VD;
typedef vector<vector<int>> VVI;
typedef long double ld;

const LL MOD = 998244353;

int vis[2502][2502];
VP V[2502];

int n, m;
vector<tuple<int, int, int>> E;

void dfs(int at, int u) {
  if (vis[u][at])
    return;
  vis[u][at] = 1;
  for (auto &p : V[at]) {
    dfs(p.first, u);
  }
}

int dist[2502];
void solve(int ks) {
  int p;
  scanf("%d %d %d", &n, &m, &p);
  FORN(i, m) {
    int a, b, c;
    scanf("%d %d %d", &a, &b, &c);
    E.push_back(make_tuple(a, b, -(c - p)));
    V[a].push_back({b, c - p});
  }
  for (int i = 1; i <= n; i++)
    dfs(i, i);

  FORAB(i, 1, n) { dist[i] = 1000000000; }
  dist[1] = 0;
  int edit;
  FORAB(i, 1, n) {
    edit = 0;
    for (auto &p : E) {
      if (dist[get<0>(p)] + get<2>(p) < dist[get<1>(p)]) {
        if (vis[1][get<0>(p)] && vis[get<1>(p)][n]) {
          edit = 1;
        }
        dist[get<1>(p)] = dist[get<0>(p)] + get<2>(p);
      }
    }
  }

  LL ans = 0;
  if (edit) {
    ans = -1;
  } else {
    ans = -dist[n];
    if (ans < 0)
      ans = 0;
  }
  printf("%lld\n", ans);
}

int main() {
#ifdef LOCAL
  double start_time = clock();
  freopen("C:\\Home\\ContestCodes\\sample.in", "r", stdin);
  //	freopen("out.out", "w", stdout);
#endif

  if (0) {
    int T;
    scanf("%d", &T);
    // AIN(T, 1, 25);
    for (int ks = 1; ks <= T; ks++) {
      solve(ks);
      fprintf(stderr, "%d done\n", ks);
    }
  } else {
    solve(0);
  }

#ifdef LOCAL
  double end_time = clock();
  fprintf(stderr, "Time = %lf\n", (end_time - start_time) / CLOCKS_PER_SEC);
#endif

  return 0;
}