Problem p02603 (C++) — buggy submission, verdict: Time Limit Exceeded

const int isDebugMode = 1;
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<long long, long long> P;
struct edge {
  long long to, cost;
};
const int inf = 1 << 27;
const long long INF = 1LL << 60;
const int COMBMAX = 1001001;
const long long MOD = 1000000007;
const long long dy[] = {-1, 0, 0, 1};
const long long dx[] = {0, -1, 1, 0};
string abc = "abcdefghijklmnopqrstuvwxyz";
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define eachdo(v, e) for (const auto &e : (v))
#define all(v) (v).begin(), (v).end()
#define lower_index(v, e)                                                      \\
  (long long)distance((v).begin(), lower_bound((v).begin(), (v).end(), e))
#define upper_index(v, e)                                                      \\
  (long long)distance((v).begin(), upper_bound((v).begin(), (v).end(), e))
long long mpow(long long a, long long n, long long mod = MOD) {
  long long res = 1;
  while (n > 0) {
    if (n & 1)
      res = res * a % mod;
    a = a * a % mod;
    n >>= 1;
  }
  return res;
}
void pt() {
  cout << endl;
  return;
}
template <class Head> void pt(Head &&head) {
  cout << head;
  pt();
  return;
}
template <class Head, class... Tail> void pt(Head &&head, Tail &&...tail) {
  cout << head << " ";
  pt(forward<Tail>(tail)...);
}
void dpt() {
  if (!isDebugMode)
    return;
  cout << endl;
  return;
}
template <class Head> void dpt(Head &&head) {
  if (!isDebugMode)
    return;
  cout << head;
  pt();
  return;
}
template <class Head, class... Tail> void dpt(Head &&head, Tail &&...tail) {
  if (!isDebugMode)
    return;
  cout << head << " ";
  pt(forward<Tail>(tail)...);
}
template <class T> void debug(T v) {
  if (!isDebugMode)
    return;
  rep(i, v.size()) cout << v[i] << " ";
  cout << endl;
}
template <class T> void debug2(T v) {
  if (!isDebugMode)
    return;
  rep(i, v.size()) {
    rep(j, v[i].size()) cout << v[i][j] << " ";
    cout << endl;
  }
}
template <class T1, class T2> inline bool chmin(T1 &a, T2 b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class T1, class T2> inline bool chmax(T1 &a, T2 b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T1, class T2> long long recgcd(T1 a, T2 b) {
  return a % b ? recgcd(b, a % b) : b;
}
bool valid(long long H, long long W, long long h, long long w) {
  return 0 <= h && h < H && 0 <= w && w < W;
}

int main() {
  ll N;
  cin >> N;
  vector<ll> a(N);
  rep(i, N) cin >> a[i];
  vector<ll> dp(N + 1, -1);
  dp[0] = 1000;
  rep(i, N) {
    dp[i + 1] = dp[i];
    rep(j, i) { chmax(dp[i + 1], dp[j] % a[j] + (dp[j] / a[j]) * a[i]); }
  }
  pt(dp[N]);
  return 0;
}

Error: TLE

Fixed submission:

const int isDebugMode = 1;
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<long long, long long> P;
struct edge {
  long long to, cost;
};
const int inf = 1 << 27;
const long long INF = 1LL << 60;
const int COMBMAX = 1001001;
const long long MOD = 1000000007;
const long long dy[] = {-1, 0, 0, 1};
const long long dx[] = {0, -1, 1, 0};
string abc = "abcdefghijklmnopqrstuvwxyz";
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define eachdo(v, e) for (const auto &e : (v))
#define all(v) (v).begin(), (v).end()
#define lower_index(v, e)                                                      \\
  (long long)distance((v).begin(), lower_bound((v).begin(), (v).end(), e))
#define upper_index(v, e)                                                      \\
  (long long)distance((v).begin(), upper_bound((v).begin(), (v).end(), e))
long long mpow(long long a, long long n, long long mod = MOD) {
  long long res = 1;
  while (n > 0) {
    if (n & 1)
      res = res * a % mod;
    a = a * a % mod;
    n >>= 1;
  }
  return res;
}
void pt() {
  cout << endl;
  return;
}
template <class Head> void pt(Head &&head) {
  cout << head;
  pt();
  return;
}
template <class Head, class... Tail> void pt(Head &&head, Tail &&...tail) {
  cout << head << " ";
  pt(forward<Tail>(tail)...);
}
void dpt() {
  if (!isDebugMode)
    return;
  cout << endl;
  return;
}
template <class Head> void dpt(Head &&head) {
  if (!isDebugMode)
    return;
  cout << head;
  pt();
  return;
}
template <class Head, class... Tail> void dpt(Head &&head, Tail &&...tail) {
  if (!isDebugMode)
    return;
  cout << head << " ";
  pt(forward<Tail>(tail)...);
}
template <class T> void debug(T v) {
  if (!isDebugMode)
    return;
  rep(i, v.size()) cout << v[i] << " ";
  cout << endl;
}
template <class T> void debug2(T v) {
  if (!isDebugMode)
    return;
  rep(i, v.size()) {
    rep(j, v[i].size()) cout << v[i][j] << " ";
    cout << endl;
  }
}
template <class T1, class T2> inline bool chmin(T1 &a, T2 b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class T1, class T2> inline bool chmax(T1 &a, T2 b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T1, class T2> long long recgcd(T1 a, T2 b) {
  return a % b ? recgcd(b, a % b) : b;
}
bool valid(long long H, long long W, long long h, long long w) {
  return 0 <= h && h < H && 0 <= w && w < W;
}

int main() {
  ll N;
  cin >> N;
  vector<ll> a(N);
  rep(i, N) cin >> a[i];
  vector<vector<ll>> dp(N + 1, vector<ll>(10000, -1));
  dp[0][0] = 1000;
  rep(i, N) rep(j, 10000) {
    rep(k, 10000) {
      if (dp[i][k] >= 0 && dp[i][k] + (k - j) * a[i] >= 0)
        chmax(dp[i + 1][j], dp[i][k] + (k - j) * a[i]);
    }
  }
  pt(dp[N][0]);
  return 0;
}