Problem p02603 (C++) — buggy submission, verdict: Runtime Error

#include <bits/stdc++.h>
#include <ext/hash_map>
#include <ext/numeric>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/detail/standard_policies.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;

#define REP(i, n) for ((i) = 0; (i) < (n); (i)++)
#define rep(i, x, n) for ((i) = (x); (i) < (n); (i)++)
#define REV(i, n) for ((i) = (n); (i) >= 0; (i)--)
#define FORIT(it, x) for ((it) = (x).begin(); (it) != (x).end(); (it)++)
#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 foreach2d(i, j, v)                                                     \\
  foreach (i, v)                                                               \\
    foreach (j, *i)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define SZ(x) ((int)(x).size())
#define MMS(x, n) memset(x, n, sizeof(x))
#define mms(x, n, s) memset(x, n, sizeof(x) * s)
#define pb push_back
#define mp make_pair
#define NX next_permutation
#define UN(x) sort(all(x)), x.erase(unique(all(x)), x.end())
#define CV(x, n) count(all(x), (n))
#define FIND(x, n) find(all(x), (n)) - (x).begin()
#define ACC(x) accumulate(all(x), 0)
#define PPC(x) __builtin_popcountll(x)
#define LZ(x) __builtin_clz(x)
#define TZ(x) __builtin_ctz(x)
#define mxe(x) *max_element(all(x))
#define mne(x) *min_element(all(x))
#define low(x, i) lower_bound(all(x), i)
#define upp(x, i) upper_bound(all(x), i)
#define NXPOW2(x) (1ll << ((int)log2(x) + 1))
#define PR(x) cout << #x << " = " << (x) << endl;

typedef unsigned long long ull;
typedef long long ll;
typedef vector<int> vi;
typedef vector<vector<int>> vvi;
typedef pair<int, int> pii;
typedef tree<int, null_type, less<int>, rb_tree_tag,
             tree_order_statistics_node_update>
    ordered_set;

const int OO = (int)2e9;
const double eps = 1e-9;

const int N = 81;

int n;
ll a[N];

int main() {
  std::ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
#ifndef ONLINE_JUDGE
//	freopen("in.txt", "rt", stdin);
//	freopen("out.txt", "wt", stdout);
#endif
  cin >> n;
  for (int i = 0; i < n; i++)
    cin >> a[i];
  ll res = 1000;
  for (int i = 0; i < n; i++) {
    int j = i + 1;
    for (; j < n; j++) {
      if (a[j] > a[j - 1]) {
        break;
      }
    }
    if (j == n)
      break;
    res = res % a[j - 1] + res / a[j - 1] * a[j];
    i = j - 1;
  }
  cout << res << endl;
  return 0;
}


Error: -11

Fixed submission:

#include <bits/stdc++.h>
#include <ext/hash_map>
#include <ext/numeric>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/detail/standard_policies.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;

#define REP(i, n) for ((i) = 0; (i) < (n); (i)++)
#define rep(i, x, n) for ((i) = (x); (i) < (n); (i)++)
#define REV(i, n) for ((i) = (n); (i) >= 0; (i)--)
#define FORIT(it, x) for ((it) = (x).begin(); (it) != (x).end(); (it)++)
#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 foreach2d(i, j, v)                                                     \\
  foreach (i, v)                                                               \\
    foreach (j, *i)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define SZ(x) ((int)(x).size())
#define MMS(x, n) memset(x, n, sizeof(x))
#define mms(x, n, s) memset(x, n, sizeof(x) * s)
#define pb push_back
#define mp make_pair
#define NX next_permutation
#define UN(x) sort(all(x)), x.erase(unique(all(x)), x.end())
#define CV(x, n) count(all(x), (n))
#define FIND(x, n) find(all(x), (n)) - (x).begin()
#define ACC(x) accumulate(all(x), 0)
#define PPC(x) __builtin_popcountll(x)
#define LZ(x) __builtin_clz(x)
#define TZ(x) __builtin_ctz(x)
#define mxe(x) *max_element(all(x))
#define mne(x) *min_element(all(x))
#define low(x, i) lower_bound(all(x), i)
#define upp(x, i) upper_bound(all(x), i)
#define NXPOW2(x) (1ll << ((int)log2(x) + 1))
#define PR(x) cout << #x << " = " << (x) << endl;

typedef unsigned long long ull;
typedef long long ll;
typedef vector<int> vi;
typedef vector<vector<int>> vvi;
typedef pair<int, int> pii;
typedef tree<int, null_type, less<int>, rb_tree_tag,
             tree_order_statistics_node_update>
    ordered_set;

const int OO = (int)2e9;
const double eps = 1e-9;

const int N = 81;

int n;
int a[N];
int dp[N][40001][41];

int calc(int idx, int sum, int stk) {
  if (idx == n)
    return sum;
  int &ret = dp[idx][sum][stk];
  if (ret != -1)
    return ret;
  ret = 0;
  for (int i = 0; i * a[idx] <= sum; i++) {
    ret = max(ret, calc(idx + 1, sum - i * a[idx], stk + i));
  }
  for (int i = 1; i <= stk; i++) {
    ret = max(ret, calc(idx + 1, sum + i * a[idx], stk - i));
  }
  return ret;
}

int main() {
  std::ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
#ifndef ONLINE_JUDGE
//	freopen("in.txt", "rt", stdin);
//	freopen("out.txt", "wt", stdout);
#endif
  cin >> n;
  for (int i = 0; i < n; i++)
    cin >> a[i];
  MMS(dp, -1);
  cout << calc(0, 1000, 0) << endl;
  return 0;
}