Problem p01096 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define stoi stoll
using ll = long long;
using vi = vector<int>;
using pii = pair<int, int>;
#define ALL(c) begin(c), end(c)
#define RALL(c) rbegin(c), rend(c)
#define ITR(i, b, e) for (auto i = (b); i != (e); ++i)
#define FORE(x, c) for (auto &&x : c)
#define REPF(i, a, n) for (int i = a, i##len = (int)(n); i < i##len; ++i)
#define REP(i, n) REPF(i, 0, n)
#define REPR(i, n) for (int i = (int)(n); i >= 0; --i)
#define SZ(c) ((int)c.size())
#define CONTAIN(c, x) (c.find(x) != end(c))
#define INSEG(l, x, r) ((l) <= (x) && (x) < (r))
#define dump(...)
#define pb push_back
#define _ 0
const signed INF_ = 1001001001;
const long long INF = 1001001001001001001LL;
const int DX[9] = {0, 1, 0, -1, 1, 1, -1, -1, 0},
          DY[9] = {-1, 0, 1, 0, -1, 1, 1, -1, 0};
template <class T> ostream &operator<<(ostream &os, const vector<T> &v) {
  ITR(i, begin(v), end(v)) os << *i << (i == end(v) - 1 ? "" : " ");
  return os;
}
template <class T> istream &operator>>(istream &is, vector<T> &v) {
  ITR(i, begin(v), end(v)) is >> *i;
  return is;
}
template <class T, class U> istream &operator>>(istream &is, pair<T, U> &p) {
  is >> p.first >> p.second;
  return is;
}
template <class T, class U> bool chmax(T &a, const U &b) {
  return a < b ? a = b, 1 : 0;
}
template <class T, class U> bool chmin(T &a, const U &b) {
  return a > b ? a = b, 1 : 0;
}
template <class T> void PSUM(T &c) { partial_sum(begin(c), end(c), begin(c)); }
template <class T> using heap = priority_queue<T, vector<T>, greater<T>>;
struct before_main_function {
  before_main_function() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << setprecision(15) << fixed;
    // #define endl "\\n"
  }
} before_main_function;
//------------------8<------------------------------------8<--------------------

int n;
vector<int> w;
int memo[300][300];

// [l, r]
int rec(int l, int r) {
  auto &MEMO = memo[l][r];
  if (MEMO != INF)
    return MEMO;
  if (r <= l)
    return 0;

  int ret = 0;
  if (abs(w[l] - w[r]) <= 1 && rec(l + 1, r - 1) == (r - 1) - (l + 1) + 1) {
    chmax(ret, r - l + 1);
  }
  REPF(i, l, r) { chmax(ret, rec(l, i) + rec(i + 1, r)); }
  return MEMO = ret;
}

signed main() {
  while (1) {
    cin >> n;
    if (n == 0)
      break;
    REP(i, 300) REP(j, 300) memo[i][j] = INF;
    w.resize(n);
    cin >> w;
    cout << rec(0, n - 1) << endl;
  }
  return (0 ^ _ ^ 0);
}


Error: TLE

Fixed submission:

#include <bits/stdc++.h>
using namespace std;
#define int long long
using ll = long long;
using vi = vector<int>;
using vl = vector<long long>;
using pii = pair<int, int>;
using pll = pair<long long, long long>;
#define ITR(i, c) for (auto i = begin(c); i != end(c); ++i)
#define FORE(x, c) for (auto &x : c)
#define REPF(i, a, n) for (int i = a, i##len = (int)(n); i < i##len; ++i)
#define REP(i, n) REPF(i, 0, n)
#define REPR(i, n) for (int i = (int)(n); i >= 0; --i)
#define REPW(i, n) for (i = 0; i < (int)(n); ++i)
#define ALL(c) begin(c), end(c)
#define RALL(c) rbegin(c), rend(c) // c++14
#define SZ(c) ((int)c.size())
#define EXIST(c, x) (c.find(x) != end(c))
#define OUTOFRANGE(y, x, h, w) (y < 0 || x < 0 || y >= h || x >= w)
#define dump(...)
const int DX[9] = {0, 1, 0, -1, 1, 1, -1, -1, 0},
          DY[9] = {-1, 0, 1, 0, -1, 1, 1, -1, 0};
#define INF (1001001001)
#define INFLL (1001001001001001001ll)
template <class T> ostream &operator<<(ostream &os, const vector<T> &v) {
  ITR(i, v) os << *i << (i == end(v) - 1 ? "" : " ");
  return os;
}
template <class T> istream &operator>>(istream &is, vector<T> &v) {
  ITR(i, v) is >> *i;
  return is;
}
template <class T> istream &operator>>(istream &is, pair<T, T> &p) {
  is >> p.first >> p.second;
  return is;
}
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}
//------------------------------------------------------------------------------
struct before_main_function {
  before_main_function() {
#ifdef int
#undef INF
#define INF INFLL
#define stoi stoll
#endif
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << setprecision(15) << fixed;
  }
} before_main_function;
//------------------------------------------------------------------------------

int dp[301][301];
vi w;
int rec(int l, int r) {
  if (dp[l][r] != INF)
    return dp[l][r];
  if (l == r)
    return dp[l][r] = 0;
  int ret = 0;
  REPF(i, l, r) {
    REPF(j, i + 1, r) {
      if (abs(w[i] - w[j]) <= 1) {
        int tmp = 0;
        tmp += rec(l, i) + rec(j + 1, r);
        if (rec(i + 1, j) == j - i - 1) {
          tmp += (j - i - 1) + 2;
        }
        chmax(ret, tmp);
      }
    }
  }
  return dp[l][r] = ret;
}
signed main() {
  while (1) {
    int n;
    cin >> n;
    if (n == 0)
      break;
    REP(i, 301) REP(j, 301) dp[i][j] = INF;

    w = vi(n);
    cin >> w;
    cout << rec(0, n) << endl;
  }
  return 0;
}