Problem p03452 (C++)

Buggy submission (status: Runtime Error):
#include <cassert>
// PXjUXeZStdX
#include <ccomplex>
#include <cctype>
#include <cerrno>
#include <cfenv>
#include <cfloat>
#include <cinttypes>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstdbool>
#include <cstddef>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctgmath>
#include <ctime>
#include <cwchar>
#include <cwctype>

// C++
#include <algorithm>
#include <array>
#include <atomic>
#include <bitset>
#include <chrono>
#include <complex>
#include <condition_variable>
#include <deque>
#include <exception>
#include <forward_list>
#include <fstream>
#include <functional>
#include <future>
#include <initializer_list>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <mutex>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <system_error>
#include <thread>
#include <tuple>
#include <type_traits>
#include <typeindex>
#include <typeinfo>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <valarray>
#include <vector>
// #include <boost/foreach.hpp>
// #include <boost/range/algorithm.hpp>
#define rep(i, j, k) for (int i = (int)j; i < (int)k; i++)
#define ll long long
#define Sort(v) sort(all(v))
// #define INF 1e9
#define LINF (1LL << 40)
#define END return 0
#define pb push_back
#define se second
#define fi first
#define pb push_back
#define all(v) (v).begin(), (v).end()
#define MP make_pair
#define int long long
using namespace std;
int day[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
// int dx[]={0,1,0,-1};
// int dy[]={1,0,-1,0};
typedef pair<int, int> P;

const long long MOD = 1000000007LL;
bool isupper(char c) {
  if ('A' <= c && c <= 'Z')
    return 1;
  return 0;
}
bool islower(char c) {
  if ('a' <= c && c <= 'z')
    return 1;
  return 0;
}
bool iskaibun(string s) {
  for (int i = 0; i < s.size() / 2; i++)
    if (s[i] != s[s.size() - i - 1])
      return 0;
  return 1;
}
bool isnumber(char c) { return ('0' <= c && c <= '9'); }
bool isalpha(char c) { return (isupper(c) || islower(c)); }
template <typename T> void print(vector<T> v) {
  for (int i = 0; i < v.size(); i++) {
    if (i)
      cout << " ";
    cout << v[i];
  }
  cout << endl;
}
int INF = 1e18;

template <typename T> void printendl(vector<T> v) {
  for (auto date : v)
    cout << date << endl;
}

template <typename T> void printvv(vector<vector<T>> v) {
  for (int i = 0; i < v.size(); i++) {
    for (int j = 0; j < v[i].size(); j++) {
      if (j)
        cout << " ";
      cout << v[i][j];
    }
    cout << endl;
  }
}
int gcd(int a, int b) {
  if (a < b)
    swap(a, b);
  if (b == 0)
    return a;
  else
    return gcd(b, a % b);
}

struct Edge {
  int to, cost;
};

struct S {
  int time, money;
};
vector<vector<Edge>> g(10010);
int n, m;

bool solve() {
  vector<int> vis(n, 0), cost(n, 0);
  rep(j, 0, n) {
    if (vis[j] == 0) {
      vis[j] = 1;
      cost[j] = 0;
      queue<int> que;
      que.push(j);

      while (!que.empty()) {
        int now = que.front();
        que.pop();

        rep(i, 0, g[now].size()) {
          if (vis[g[now][i].to]) {
            if (cost[g[now][i].to] != cost[now] + g[now][i].cost)
              return false;
          } else {
            cost[g[now][i].to] = cost[now] + g[now][i].cost;
            vis[g[now][i].to] = 1;
            que.push(g[now][i].to);
          }
        }
      }
    }
  }
  return true;
}

signed main() {
  cin >> n >> m;
  rep(i, 0, m) {
    int l, r, c;
    cin >> l >> r >> c;
    l--;
    r--;
    g[l].push_back(Edge{r, c});
    g[r].push_back(Edge{l, -c});
  }
  bool ans = solve();
  if (ans)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
}
/*

*/


Fixed submission:
#include <cassert>
// PXjUXeZStdX
#include <ccomplex>
#include <cctype>
#include <cerrno>
#include <cfenv>
#include <cfloat>
#include <cinttypes>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstdbool>
#include <cstddef>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctgmath>
#include <ctime>
#include <cwchar>
#include <cwctype>

// C++
#include <algorithm>
#include <array>
#include <atomic>
#include <bitset>
#include <chrono>
#include <complex>
#include <condition_variable>
#include <deque>
#include <exception>
#include <forward_list>
#include <fstream>
#include <functional>
#include <future>
#include <initializer_list>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <mutex>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <system_error>
#include <thread>
#include <tuple>
#include <type_traits>
#include <typeindex>
#include <typeinfo>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <valarray>
#include <vector>
// #include <boost/foreach.hpp>
// #include <boost/range/algorithm.hpp>
#define rep(i, j, k) for (int i = (int)j; i < (int)k; i++)
#define ll long long
#define Sort(v) sort(all(v))
// #define INF 1e9
#define LINF (1LL << 40)
#define END return 0
#define pb push_back
#define se second
#define fi first
#define pb push_back
#define all(v) (v).begin(), (v).end()
#define MP make_pair
#define int long long
using namespace std;
int day[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
// int dx[]={0,1,0,-1};
// int dy[]={1,0,-1,0};
typedef pair<int, int> P;

const long long MOD = 1000000007LL;
bool isupper(char c) {
  if ('A' <= c && c <= 'Z')
    return 1;
  return 0;
}
bool islower(char c) {
  if ('a' <= c && c <= 'z')
    return 1;
  return 0;
}
bool iskaibun(string s) {
  for (int i = 0; i < s.size() / 2; i++)
    if (s[i] != s[s.size() - i - 1])
      return 0;
  return 1;
}
bool isnumber(char c) { return ('0' <= c && c <= '9'); }
bool isalpha(char c) { return (isupper(c) || islower(c)); }
template <typename T> void print(vector<T> v) {
  for (int i = 0; i < v.size(); i++) {
    if (i)
      cout << " ";
    cout << v[i];
  }
  cout << endl;
}
int INF = 1e18;

template <typename T> void printendl(vector<T> v) {
  for (auto date : v)
    cout << date << endl;
}

template <typename T> void printvv(vector<vector<T>> v) {
  for (int i = 0; i < v.size(); i++) {
    for (int j = 0; j < v[i].size(); j++) {
      if (j)
        cout << " ";
      cout << v[i][j];
    }
    cout << endl;
  }
}
int gcd(int a, int b) {
  if (a < b)
    swap(a, b);
  if (b == 0)
    return a;
  else
    return gcd(b, a % b);
}

struct Edge {
  int to, cost;
};

struct S {
  int time, money;
};
vector<vector<Edge>> g(100100);
int n, m;

bool solve() {
  vector<int> vis(n, 0), cost(n, 0);
  rep(j, 0, n) {
    if (vis[j] == 0) {
      vis[j] = 1;
      cost[j] = 0;
      queue<int> que;
      que.push(j);

      while (!que.empty()) {
        int now = que.front();
        que.pop();

        rep(i, 0, g[now].size()) {
          if (vis[g[now][i].to]) {
            if (cost[g[now][i].to] != cost[now] + g[now][i].cost)
              return false;
          } else {
            cost[g[now][i].to] = cost[now] + g[now][i].cost;
            vis[g[now][i].to] = 1;
            que.push(g[now][i].to);
          }
        }
      }
    }
  }
  return true;
}

signed main() {
  cin >> n >> m;
  rep(i, 0, m) {
    int l, r, c;
    cin >> l >> r >> c;
    l--;
    r--;
    g[l].push_back(Edge{r, c});
    g[r].push_back(Edge{l, -c});
  }
  bool ans = solve();
  if (ans)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
}
/*

*/