Problem p02709 (C++) — buggy submission, verdict: Runtime Error

#include <bits/stdc++.h>
#include <type_traits>
using namespace std;

using ll = long long;

#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rrep(i, n) for (int i = 1; i <= (n); ++i)
#define drep(i, n) for (int i = (n)-1; i >= 0; --i)
#define ddrep(i, n) for (int i = n; i > 0; --i)
#define srep(i, s, t) for (int i = s; i < t; ++i)
#define ssrep(i, s, t) for (int i = s; i <= t; ++i)

#define rng(a) a.begin(), a.end()
#define rrng(a) a.rbegin(), a.rend()
#define pb push_back
#define eb emplace_back
#define fi first
#define se second

#define chmax(x, y) (x = max(x, y))
#define chmin(x, y) (x = min(x, y))

using pi = pair<int, int>;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using ld = long double;

template <class T, class U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
  os << "(" << p.first << "," << p.second << ")";
  return os;
}

template <class T> ostream &operator<<(ostream &os, const vector<T> &v) {
  os << "{";
  rep(i, (int)v.size()) {
    if (i)
      os << ",";
    os << v[i];
  }
  os << "}";
  return os;
}

template <typename T, size_t S> void printArray(const T (&array)[S]) {
  for (auto val : array)
    std::cout << val << ", ";
  std::cout << "\\n";
}

const int mod = 1e9 + 7;
const int inf = 1e9 + 5;

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << std::setprecision(10);

  int n;
  std::cin >> n;
  vector<pair<ll, ll>> a;
  rep(i, n) {
    int ai;
    std::cin >> ai;
    a.pb({ai, i + 1});
  }
  sort(rrng(a));
  vvl dp(n + 1, vl(n + 1));
  rrep(i, n) {
    rep(j, i) {
      chmax(dp[i][j + 1],
            dp[i - 1][j] + a[i - 1].fi * abs(a[i - 1].se - (j + 1)));
      chmax(dp[i][j], dp[i - 1][j] +
                          a[i - 1].fi * abs(a[i - 1].se - (n - ((i - 1) - j))));
    }
  }
  ll ans = 0;
  rep(i, n) chmax(ans, dp[n][i]);
  std::cout << ans << "\\n";
}


Error: 0

Fixed submission:

#include <bits/stdc++.h>
#include <type_traits>
using namespace std;

using ll = long long;

#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rrep(i, n) for (int i = 1; i <= (n); ++i)
#define drep(i, n) for (int i = (n)-1; i >= 0; --i)
#define ddrep(i, n) for (int i = n; i > 0; --i)
#define srep(i, s, t) for (int i = s; i < t; ++i)
#define ssrep(i, s, t) for (int i = s; i <= t; ++i)

#define rng(a) a.begin(), a.end()
#define rrng(a) a.rbegin(), a.rend()
#define pb push_back
#define eb emplace_back
#define fi first
#define se second

#define chmax(x, y) (x = max(x, y))
#define chmin(x, y) (x = min(x, y))

using pi = pair<int, int>;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using ld = long double;

template <class T, class U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
  os << "(" << p.first << "," << p.second << ")";
  return os;
}

template <class T> ostream &operator<<(ostream &os, const vector<T> &v) {
  os << "{";
  rep(i, (int)v.size()) {
    if (i)
      os << ",";
    os << v[i];
  }
  os << "}";
  return os;
}

template <typename T, size_t S> void printArray(const T (&array)[S]) {
  for (auto val : array)
    std::cout << val << ", ";
  std::cout << "\\n";
}

const int mod = 1e9 + 7;
const int inf = 1e9 + 5;

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << std::setprecision(10);

  int n;
  std::cin >> n;
  vector<pi> a;
  rep(i, n) {
    int ai;
    std::cin >> ai;
    a.pb({ai, i + 1});
  }
  sort(rrng(a));
  vvl dp(n + 1, vl(n));
  rrep(i, n) {
    rep(j, i) {
      chmax(dp[i][j + 1],
            dp[i - 1][j] + a[i - 1].fi * abs(a[i - 1].se - (j + 1)));
      chmax(dp[i][j], dp[i - 1][j] +
                          a[i - 1].fi * abs(a[i - 1].se - (n - ((i - 1) - j))));
    }
  }
  ll ans = 0;
  rep(i, n) chmax(ans, dp[n][i]);
  std::cout << ans << "\\n";
}