Problem p01423 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <algorithm>
#include <bitset>
#include <cassert>
#include <cfloat>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <memory>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>

using namespace std;

#define rep(i, n) for (int i = 0; i < (int)(n); ++i)
#define foreach(it, c)                                                         \\
  for (__typeof__((c).begin()) it = (c).begin(); it != (c).end(); ++it)
#define rforeach(it, c)                                                        \\
  for (__typeof__((c).rbegin()) it = (c).rbegin(); it != (c).rend(); ++it)
#define all(c) (c).begin(), (c).end()
#define rall(c) (c).rbegin(), (c).rend()
#define CL(arr, val) memset(arr, val, sizeof(arr))
#define COPY(dest, src) memcpy(dest, src, sizeof(dest))
#define ten(n) ((long long)(1e##n))
#define bin(n) (1LL << (n))
#define erep(i, n) for (int i = 0; i <= (int)(n); ++i)
#define revrep(i, n) for (int i = (n); i >= 0; --i)
#define pb push_back

template <class T> void chmax(T &a, const T &b) { a = max(a, b); }
template <class T> void chmin(T &a, const T &b) { a = min(a, b); }

template <class T> void uniq(T &c) {
  sort(c.begin(), c.end());
  c.erase(unique(c.begin(), c.end()), c.end());
}

template <class T> string to_s(const T &a) {
  ostringstream os;
  os << a;
  return os.str();
}
template <class T> T to_T(const string &s) {
  istringstream is(s);
  T res;
  is >> res;
  return res;
}

template <typename T> void print_container(ostream &os, const T &c) {
  const char *_s = " ";
  if (!c.empty()) {
    __typeof__(c.begin()) last = --c.end();
    foreach (it, c) {
      os << *it;
      if (it != last)
        cout << _s;
    }
  }
}
template <typename T> ostream &operator<<(ostream &os, const vector<T> &c) {
  print_container(os, c);
  return os;
}
template <typename T> ostream &operator<<(ostream &os, const set<T> &c) {
  print_container(os, c);
  return os;
}
template <typename T> ostream &operator<<(ostream &os, const multiset<T> &c) {
  print_container(os, c);
  return os;
}
template <typename T> ostream &operator<<(ostream &os, const deque<T> &c) {
  print_container(os, c);
  return os;
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const map<T, U> &c) {
  print_container(os, c);
  return os;
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
  os << "( " << p.first << ", " << p.second << " )";
  return os;
}

template <class T>
void print(T a, int n, const string &deli = " ", int br = 1) {
  for (int i = 0; i < n; ++i) {
    cout << a[i];
    if (i + 1 != n)
      cout << deli;
  }
  while (br--)
    cout << endl;
}
template <class T> void print2d(T a, int w, int h, int width = -1, int br = 1) {
  for (int i = 0; i < h; ++i) {
    for (int j = 0; j < w; ++j) {
      if (width != -1)
        cout.width(width);
      cout << a[i][j] << ' ';
    }
    cout << endl;
  }
  while (br--)
    cout << endl;
}

template <class T> void input(T &a, int n) {
  for (int i = 0; i < n; ++i)
    cin >> a[i];
}
template <class T> void input(T *a, int n) {
  for (int i = 0; i < n; ++i)
    cin >> a[i];
}

void fix_pre(int n) {
  cout.setf(ios::fixed, ios::floatfield);
  cout.precision(10);
}
void fast_io() {
  cin.tie(0);
  ios::sync_with_stdio(false);
}
#define trace(x) (cout << #x << ": " << (x) << endl)

bool in_rect(int x, int y, int w, int h) {
  return 0 <= x && x < w && 0 <= y && y < h;
}

typedef long long ll;
typedef pair<int, int> pint;

// y(v): v>^<  y(^): ^>v<
const int dx[] = {0, 1, 0, -1};
const int dy[] = {1, 0, -1, 0};

const double PI = acos(-1.0);
#define mp make_pair

int n;
int g[128][128];
int res;
vector<int> used;
void dfs(int depth) {
  if (depth == n) {
    if (used.size() >= 2) {
      int score = 0;
      rep(i, used.size()) {
        int s = ten(9);
        rep(j, used.size()) if (i != j) chmin(s, g[used[i]][used[j]]);
        score += s;
      }
      chmax(res, score);
    }
    return;
  }

  dfs(depth + 1);

  bool can_use = true;
  rep(i, used.size()) can_use &= g[used[i]][depth] != -1;
  if (can_use) {
    used.pb(depth);
    dfs(depth + 1);
    used.pop_back();
  }
}
int main() {
  int m;
  cin >> n >> m;
  CL(g, -1);
  rep(i, m) {
    int u, v, f;
    cin >> u >> v >> f;
    --u, --v;
    g[u][v] = g[v][u] = f;
  }

  dfs(0);
  cout << res << endl;
}

Error: TLE

Fixed submission:

#include <algorithm>
#include <bitset>
#include <cassert>
#include <cfloat>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <memory>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>

using namespace std;

#define rep(i, n) for (int i = 0; i < (int)(n); ++i)
#define foreach(it, c)                                                         \\
  for (__typeof__((c).begin()) it = (c).begin(); it != (c).end(); ++it)
#define rforeach(it, c)                                                        \\
  for (__typeof__((c).rbegin()) it = (c).rbegin(); it != (c).rend(); ++it)
#define all(c) (c).begin(), (c).end()
#define rall(c) (c).rbegin(), (c).rend()
#define CL(arr, val) memset(arr, val, sizeof(arr))
#define COPY(dest, src) memcpy(dest, src, sizeof(dest))
#define ten(n) ((long long)(1e##n))
#define bin(n) (1LL << (n))
#define erep(i, n) for (int i = 0; i <= (int)(n); ++i)
#define revrep(i, n) for (int i = (n); i >= 0; --i)
#define pb push_back

template <class T> void chmax(T &a, const T &b) { a = max(a, b); }
template <class T> void chmin(T &a, const T &b) { a = min(a, b); }

template <class T> void uniq(T &c) {
  sort(c.begin(), c.end());
  c.erase(unique(c.begin(), c.end()), c.end());
}

template <class T> string to_s(const T &a) {
  ostringstream os;
  os << a;
  return os.str();
}
template <class T> T to_T(const string &s) {
  istringstream is(s);
  T res;
  is >> res;
  return res;
}

template <typename T> void print_container(ostream &os, const T &c) {
  const char *_s = " ";
  if (!c.empty()) {
    __typeof__(c.begin()) last = --c.end();
    foreach (it, c) {
      os << *it;
      if (it != last)
        cout << _s;
    }
  }
}
template <typename T> ostream &operator<<(ostream &os, const vector<T> &c) {
  print_container(os, c);
  return os;
}
template <typename T> ostream &operator<<(ostream &os, const set<T> &c) {
  print_container(os, c);
  return os;
}
template <typename T> ostream &operator<<(ostream &os, const multiset<T> &c) {
  print_container(os, c);
  return os;
}
template <typename T> ostream &operator<<(ostream &os, const deque<T> &c) {
  print_container(os, c);
  return os;
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const map<T, U> &c) {
  print_container(os, c);
  return os;
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
  os << "( " << p.first << ", " << p.second << " )";
  return os;
}

template <class T>
void print(T a, int n, const string &deli = " ", int br = 1) {
  for (int i = 0; i < n; ++i) {
    cout << a[i];
    if (i + 1 != n)
      cout << deli;
  }
  while (br--)
    cout << endl;
}
template <class T> void print2d(T a, int w, int h, int width = -1, int br = 1) {
  for (int i = 0; i < h; ++i) {
    for (int j = 0; j < w; ++j) {
      if (width != -1)
        cout.width(width);
      cout << a[i][j] << ' ';
    }
    cout << endl;
  }
  while (br--)
    cout << endl;
}

template <class T> void input(T &a, int n) {
  for (int i = 0; i < n; ++i)
    cin >> a[i];
}
template <class T> void input(T *a, int n) {
  for (int i = 0; i < n; ++i)
    cin >> a[i];
}

void fix_pre(int n) {
  cout.setf(ios::fixed, ios::floatfield);
  cout.precision(10);
}
void fast_io() {
  cin.tie(0);
  ios::sync_with_stdio(false);
}
#define trace(x) (cout << #x << ": " << (x) << endl)

bool in_rect(int x, int y, int w, int h) {
  return 0 <= x && x < w && 0 <= y && y < h;
}

typedef long long ll;
typedef pair<int, int> pint;

// y(v): v>^<  y(^): ^>v<
const int dx[] = {0, 1, 0, -1};
const int dy[] = {1, 0, -1, 0};

const double PI = acos(-1.0);
#define mp make_pair

int n;
int g[128][128];
int res;
set<vector<int>> visit;
vector<int> used;
vector<int> s;
void dfs() {
  // if (visit.count(used))
  //     return;
  // visit.insert(used);

  if (used.size() >= 2) {
    int score = 0;
    rep(i, used.size()) {
      int s = ten(9);
      rep(j, used.size()) if (i != j) chmin(s, g[used[i]][used[j]]);
      score += s;
    }
    chmax(res, score);
  }

  bool next[111];
  fill_n(next, n, true);
  rep(i, used.size()) rep(j, n) next[j] &= g[used[i]][j] != -1;
  rep(i, n) {
    if (next[i]) {
      used.pb(i);
      // sort(all(used));

      dfs();

      used.pop_back();
      // used.erase(find(all(used), i));
    }
  }
}
int main() {
  int m;
  cin >> n >> m;
  CL(g, -1);
  rep(i, m) {
    int u, v, f;
    cin >> u >> v >> f;
    --u, --v;
    g[u][v] = g[v][u] = f;
  }

  dfs();
  cout << res << endl;
}