Problem p03768 (C++)

Buggy submission (status: Time Limit Exceeded):
// #pragma GCC
// target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,avx512f")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <algorithm>
#include <bitset>
#include <cassert>
#include <cmath>
#include <complex>
#include <functional>
#include <immintrin.h>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <memory>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#ifdef DEBUG
#include "./Lib/Timer.hpp"
#include "./Lib/debug_VC.hpp"
#include "./Lib/sample.hpp"
#else
#define dump(...)
#endif

/* macro */
#define FOR(i, b, e) for (ll i = (ll)(b); i < (ll)(e); ++i)
#define RFOR(i, b, e) for (ll i = (ll)(e - 1); i >= (ll)(b); --i)
#define REP(i, n) FOR(i, 0, n)
#define RREP(i, n) RFOR(i, 0, n)
#define REPC(x, c) for (const auto &x : (c))
#define REPI2(it, b, e) for (auto it = (b); it != (e); ++it)
#define REPI(it, c) REPI2(it, (c).begin(), (c).end())
#define RREPI(it, c) REPI2(it, (c).rbegin(), (c).rend())
#define REPI_ERACE2(it, b, e) for (auto it = (b); it != (e);)
#define REPI_ERACE(it, c) REPI_ERACE2(it, (c).begin(), (c).end())
#define ALL(x) (x).begin(), (x).end()
#define cauto const auto &
/* macro func */
template <class T> inline auto sort(T &t) { std::sort(ALL(t)); }
template <class T> inline auto rsort(T &t) {
  std::sort((t).rbegin(), (t).rend());
}
template <class T> inline auto unique(T &t) {
  (t).erase(unique((t).begin(), (t).end()), (t).end());
}
template <class T, class S> inline auto chmax(T &t, const S &s) {
  if (s > t) {
    t = s;
    return true;
  }
  return false;
}
template <class T, class S> inline auto chmin(T &t, const S &s) {
  if (s < t) {
    t = s;
    return true;
  }
  return false;
}
inline auto BR() { std::cout << "\n"; }

/* type define */
using ll = long long;
using PAIR = std::pair<ll, ll>;
using VS = std::vector<std::string>;
using VL = std::vector<long long>;
using VVL = std::vector<VL>;
using VVVL = std::vector<VVL>;
using VD = std::vector<double>;
template <class T> using V = std::vector<T>;

/* using std */
using std::cout;
constexpr char endl = '\n';
using std::bitset;
using std::cin;
using std::list;
using std::map;
using std::multimap;
using std::multiset;
using std::pair;
using std::priority_queue;
using std::queue;
using std::set;
using std::stack;
using std::string;
using std::unordered_map;
using std::unordered_multimap;
using std::unordered_multiset;
using std::unordered_set;
using std::vector;

/* Initial processing  */
struct Preprocessing {
  Preprocessing() {
    std::cin.tie(0);
    std::ios::sync_with_stdio(0);
  };
} _Preprocessing;

/* Remove the source of the bug */
signed pow(signed, signed) {
  assert(false);
  return -1;
}

/* define hash */
namespace std {
template <> class hash<std::pair<ll, ll>> {
public:
  size_t operator()(const std::pair<ll, ll> &x) const {
    return hash<ll>()(1000000000 * x.first + x.second);
  }
};
} // namespace std

/* input */
template <class T> std::istream &operator>>(std::istream &is, vector<T> &vec) {
  for (T &x : vec)
    is >> x;
  return is;
}

/* constant value */
constexpr ll MOD = 1000000007;
// constexpr ll MOD = 998244353;

//=============================================================================================;

signed main() {
  ll n, m;
  cin >> n >> m;
  unordered_multimap<ll, ll> graph;
  REP(_, m) {
    ll a, b;
    cin >> a >> b;
    --a;
    --b;
    graph.emplace(a, b);
    graph.emplace(b, a);
  }
  ll q;
  cin >> q;
  list<pair<ll, PAIR>> que;
  REP(_, q) {
    ll v, d, c;
    cin >> v >> d >> c;
    --v;
    que.emplace_front(v, PAIR{d, c});
  }
  unordered_map<PAIR, ll> mx;
  REPC(p, graph) { mx.emplace(PAIR{p.first, p.second}, -1); }

  VL ans(n, 0);
  REPC(p, que) {
    auto v = p.first;
    auto d = p.second.first;
    auto c = p.second.second;
    // cout << "-- " << v << " --" << endl;
    V<bool> isUsed(n, false);
    isUsed[v] = true;
    queue<PAIR> q;
    q.emplace(v, 0);

    auto add = [&](ll from, ll to, ll len) {
      ll toL = d - len;
      // cout << to << " :" << toL << endl;
      if (chmax(mx[{from, to}], toL)) {
        q.emplace(to, len + 1);
        isUsed[to] = true;
      }
      // chmax(mx[{to, from}], d + len + 1);
    };

    while (!q.empty()) {
      auto from = q.front().first;
      auto len = q.front().second;
      q.pop();
      // dump(from);
      if (ans[from] == 0) {
        ans[from] = c;
      }
      auto range = graph.equal_range(from);
      REPI2(itr, range.first, range.second) {
        auto to = itr->second;
        if (!isUsed[to] && len < d) {
          add(from, to, len);
        }
      }
    }
  }
  REPC(x, ans) { cout << x << endl; }
  /**
  REPC(p, mx) {
          auto [from, to] = p.first;
          auto val = p.second;
          cout << from << " -> " << to << " : " << val << endl;
  }
  /*//**/
}

Fixed submission:
// #pragma GCC
// target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,avx512f")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <algorithm>
#include <bitset>
#include <cassert>
#include <cmath>
#include <complex>
#include <functional>
#include <immintrin.h>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <memory>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#ifdef DEBUG
#include "./Lib/Timer.hpp"
#include "./Lib/debug_VC.hpp"
#include "./Lib/sample.hpp"
#else
#define dump(...)
#endif

/* macro */
#define FOR(i, b, e) for (ll i = (ll)(b); i < (ll)(e); ++i)
#define RFOR(i, b, e) for (ll i = (ll)(e - 1); i >= (ll)(b); --i)
#define REP(i, n) FOR(i, 0, n)
#define RREP(i, n) RFOR(i, 0, n)
#define REPC(x, c) for (const auto &x : (c))
#define REPI2(it, b, e) for (auto it = (b); it != (e); ++it)
#define REPI(it, c) REPI2(it, (c).begin(), (c).end())
#define RREPI(it, c) REPI2(it, (c).rbegin(), (c).rend())
#define REPI_ERACE2(it, b, e) for (auto it = (b); it != (e);)
#define REPI_ERACE(it, c) REPI_ERACE2(it, (c).begin(), (c).end())
#define ALL(x) (x).begin(), (x).end()
#define cauto const auto &
/* macro func */
template <class T> inline auto sort(T &t) { std::sort(ALL(t)); }
template <class T> inline auto rsort(T &t) {
  std::sort((t).rbegin(), (t).rend());
}
template <class T> inline auto unique(T &t) {
  (t).erase(unique((t).begin(), (t).end()), (t).end());
}
template <class T, class S> inline auto chmax(T &t, const S &s) {
  if (s > t) {
    t = s;
    return true;
  }
  return false;
}
template <class T, class S> inline auto chmin(T &t, const S &s) {
  if (s < t) {
    t = s;
    return true;
  }
  return false;
}
inline auto BR() { std::cout << "\n"; }

/* type define */
using ll = long long;
using PAIR = std::pair<ll, ll>;
using VS = std::vector<std::string>;
using VL = std::vector<long long>;
using VVL = std::vector<VL>;
using VVVL = std::vector<VVL>;
using VD = std::vector<double>;
template <class T> using V = std::vector<T>;

/* using std */
using std::cout;
constexpr char endl = '\n';
using std::bitset;
using std::cin;
using std::list;
using std::map;
using std::multimap;
using std::multiset;
using std::pair;
using std::priority_queue;
using std::queue;
using std::set;
using std::stack;
using std::string;
using std::unordered_map;
using std::unordered_multimap;
using std::unordered_multiset;
using std::unordered_set;
using std::vector;

/* Initial processing  */
struct Preprocessing {
  Preprocessing() {
    std::cin.tie(0);
    std::ios::sync_with_stdio(0);
  };
} _Preprocessing;

/* Remove the source of the bug */
signed pow(signed, signed) {
  assert(false);
  return -1;
}

/* define hash */
namespace std {
template <> class hash<std::pair<ll, ll>> {
public:
  size_t operator()(const std::pair<ll, ll> &x) const {
    return hash<ll>()(1000000000 * x.first + x.second);
  }
};
} // namespace std

/* input */
template <class T> std::istream &operator>>(std::istream &is, vector<T> &vec) {
  for (T &x : vec)
    is >> x;
  return is;
}

/* constant value */
constexpr ll MOD = 1000000007;
// constexpr ll MOD = 998244353;

//=============================================================================================;

signed main() {
  ll n, m;
  cin >> n >> m;
  unordered_multimap<ll, ll> graph;
  REP(_, m) {
    ll a, b;
    cin >> a >> b;
    --a;
    --b;
    graph.emplace(a, b);
    graph.emplace(b, a);
  }
  ll q;
  cin >> q;
  list<pair<ll, PAIR>> que;
  REP(_, q) {
    ll v, d, c;
    cin >> v >> d >> c;
    --v;
    que.emplace_front(v, PAIR{d, c});
  }
  unordered_map<PAIR, ll> mx;
  REPC(p, graph) { mx.emplace(PAIR{p.first, p.second}, -1); }

  VL ans(n, 0);
  REPC(p, que) {
    auto v = p.first;
    auto d = p.second.first;
    auto c = p.second.second;
    // cout << "-- " << v << " --" << endl;
    V<bool> isUsed(n, false);
    isUsed[v] = true;
    queue<PAIR> q;
    q.emplace(v, 0);

    auto add = [&](ll from, ll to, ll len) {
      ll toL = d - len;
      // cout << to << " :" << toL << endl;
      if (chmax(mx[{from, to}], toL)) {
        q.emplace(to, len + 1);
        isUsed[to] = true;
      }
      chmax(mx[{to, from}], toL + 1);
    };

    while (!q.empty()) {
      auto from = q.front().first;
      auto len = q.front().second;
      q.pop();
      // dump(from);
      if (ans[from] == 0) {
        ans[from] = c;
      }
      auto range = graph.equal_range(from);
      REPI2(itr, range.first, range.second) {
        auto to = itr->second;
        if (!isUsed[to] && len < d) {
          add(from, to, len);
        }
      }
    }
  }
  REPC(x, ans) { cout << x << endl; }
  /**
  REPC(p, mx) {
          auto [from, to] = p.first;
          auto val = p.second;
          cout << from << " -> " << to << " : " << val << endl;
  }
  /*//**/
}