Problem p00899 (C++) — buggy submission, verdict: Runtime Error

#include <bits/stdc++.h>

using namespace std;

inline int toInt(string s) {
  int v;
  istringstream sin(s);
  sin >> v;
  return v;
}
template <class T> inline string toString(T x) {
  ostringstream sout;
  sout << x;
  return sout.str();
}
template <class T> inline T sqr(T x) { return x * x; }

typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<string> vs;
typedef pair<int, int> pii;
typedef long long ll;

#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()
#define pb push_back
#define mp make_pair
#define each(i, c)                                                             \\
  for (typeof((c).begin()) i = (c).begin(); i != (c).end(); ++i)
#define exist(s, e) ((s).find(e) != (s).end())
#define range(i, a, b) for (int i = (a); i < (b); ++i)
#define rep(i, n) range(i, 0, n)
#define clr(a, b) memset((a), (b), sizeof(a))
#define dump(x) cerr << #x << " = " << (x) << endl;
#define debug(x)                                                               \\
  cerr << #x << " = " << (x) << " (L" << __LINE__ << ")"                       \\
       << " " << __FILE__ << endl;

const double eps = 1e-10;
const double pi = acos(-1.0);
const ll INF = 1LL << 62;
const int inf = 1 << 29;

int main(void) {
  for (int n; cin >> n, n;) {
    vs str(n);
    rep(i, n) cin >> str[i];

    set<int> del;
    rep(i, n) {
      rep(j, n) {
        if (i == j || str[j].size() < str[i].size())
          continue;

        rep(k, str[j].size() - str[i].size()) {
          if (str[j].substr(k, str[i].size()) == str[i]) {
            del.insert(i);
          }
        }
      }
    }
    for (auto itr = del.rbegin(); itr != del.rend(); itr++) {
      str.erase(str.begin() + *itr);
    }
    n -= del.size();

    vector<vs> sub(n, vs(n));
    rep(i, n) {
      rep(j, n) {
        if (i == j)
          continue;

        sub[i][j] = str[j];
        for (int k = min(str[i].size(), str[j].size()); k > 0; k--) {
          if (str[j].substr(0, k) != str[i].substr(str[i].size() - k, k))
            continue;

          sub[i][j].erase(0, k);
          break;
        }
      }
    }

    vector<vs> dp(1 << n, vs(n));

    rep(i, 1 << n) {
      rep(j, n) {
        if (dp[i][j] == "" && i != 0)
          continue;

        rep(k, n) {
          if (i & (1 << k))
            continue;
          int next_idx = i | (1 << k);

          string next_str = dp[i][j] + (i == 0 ? str[k] : sub[j][k]);

          if (dp[next_idx][k] == "") {
            dp[next_idx][k] = next_str;
            continue;
          }

          if (dp[next_idx][k].size() > next_str.size())
            dp[next_idx][k] = next_str;
          else if (dp[next_idx][k].size() == next_str.size())
            dp[next_idx][k] = min(dp[next_idx][k], next_str);
        }
      }
    }

    string res = dp[(1 << n) - 1][0];
    range(i, 1, n) {
      if (res.size() > dp[(1 << n) - 1][i].size())
        res = dp[(1 << n) - 1][i];
      else if (res.size() == dp[(1 << n) - 1][i].size())
        res = min(res, dp[(1 << n) - 1][i]);
    }

    cout << res.size() << endl;
  }

  return 0;
}

Error: TLE

Fixed submission:

#include <bits/stdc++.h>

using namespace std;

inline int toInt(string s) {
  int v;
  istringstream sin(s);
  sin >> v;
  return v;
}
template <class T> inline string toString(T x) {
  ostringstream sout;
  sout << x;
  return sout.str();
}
template <class T> inline T sqr(T x) { return x * x; }

typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<string> vs;
typedef pair<int, int> pii;
typedef long long ll;

#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()
#define pb push_back
#define mp make_pair
#define each(i, c)                                                             \\
  for (typeof((c).begin()) i = (c).begin(); i != (c).end(); ++i)
#define exist(s, e) ((s).find(e) != (s).end())
#define range(i, a, b) for (int i = (a); i < (b); ++i)
#define rep(i, n) range(i, 0, n)
#define clr(a, b) memset((a), (b), sizeof(a))
#define dump(x) cerr << #x << " = " << (x) << endl;
#define debug(x)                                                               \\
  cerr << #x << " = " << (x) << " (L" << __LINE__ << ")"                       \\
       << " " << __FILE__ << endl;

const double eps = 1e-10;
const double pi = acos(-1.0);
const ll INF = 1LL << 62;
const int inf = 1 << 29;

int main(void) {
  for (int n; cin >> n, n;) {
    vs str(n);
    rep(i, n) cin >> str[i];

    vi del;
    rep(i, n) {
      rep(j, n) {
        if (i == j || str[j].size() < str[i].size())
          continue;

        rep(k, str[j].size() - str[i].size()) {
          if (str[j].substr(k, str[i].size()) == str[i]) {
            del.pb(i);
          }
        }
      }
    }
    for (auto idx : del)
      str.erase(str.begin() + idx);
    n -= del.size();

    vector<vs> sub(n, vs(n));
    rep(i, n) {
      rep(j, n) {
        if (i == j)
          continue;

        sub[i][j] = str[j];
        for (int k = min(str[i].size(), str[j].size()); k > 0; k--) {
          if (str[j].substr(0, k) != str[i].substr(str[i].size() - k, k))
            continue;

          sub[i][j].erase(0, k);
          break;
        }
      }
    }

    vector<vs> dp(1 << n, vs(n));

    rep(i, 1 << n) {
      rep(j, n) {
        if (dp[i][j] == "" && i != 0)
          continue;

        rep(k, n) {
          if (i & (1 << k))
            continue;
          int next_idx = i | (1 << k);

          string next_str = dp[i][j] + (i == 0 ? str[k] : sub[j][k]);

          if (dp[next_idx][k] == "") {
            dp[next_idx][k] = next_str;
            continue;
          }

          if (dp[next_idx][k].size() > next_str.size())
            dp[next_idx][k] = next_str;
          else if (dp[next_idx][k].size() == next_str.size())
            dp[next_idx][k] = min(dp[next_idx][k], next_str);
        }
      }
    }

    string res = dp[(1 << n) - 1][0];
    range(i, 1, n) res = min(res, dp[(1 << n) - 1][i]);

    cout << res.size() << endl;
  }

  return 0;
}