Problem p02665 (C++) — buggy submission, verdict: Runtime Error

#line 2 "header.hpp"

//%snippet.set('header')%
//%snippet.fold()%
#ifndef HEADER_H
#define HEADER_H

// template version 2.0
using namespace std;
#include <bits/stdc++.h>

// varibable settings
const long long INF = 1e18;
template <class T> constexpr T inf = numeric_limits<T>::max() / 2.1;

#define _overload3(_1, _2, _3, name, ...) name
#define _rep(i, n) repi(i, 0, n)
#define repi(i, a, b) for (ll i = (ll)(a); i < (ll)(b); ++i)
#define rep(...) _overload3(__VA_ARGS__, repi, _rep, )(__VA_ARGS__)
#define _rrep(i, n) rrepi(i, 0, n)
#define rrepi(i, a, b) for (ll i = (ll)((b)-1); i >= (ll)(a); --i)
#define r_rep(...) _overload3(__VA_ARGS__, rrepi, _rrep, )(__VA_ARGS__)
#define each(i, a) for (auto &&i : a)
#define all(x) (x).begin(), (x).end()
#define sz(x) ((int)(x).size())
#define pb(a) push_back(a)
#define mp(a, b) make_pair(a, b)
#define mt(...) make_tuple(__VA_ARGS__)
#define ub upper_bound
#define lb lower_bound
#define lpos(A, x) (lower_bound(all(A), x) - A.begin())
#define upos(A, x) (upper_bound(all(A), x) - A.begin())
template <class T> inline void chmax(T &a, const T &b) {
  if ((a) < (b))
    (a) = (b);
}
template <class T> inline void chmin(T &a, const T &b) {
  if ((a) > (b))
    (a) = (b);
}
template <typename X, typename T> auto make_table(X x, T a) {
  return vector<T>(x, a);
}
template <typename X, typename Y, typename Z, typename... Zs>
auto make_table(X x, Y y, Z z, Zs... zs) {
  auto cont = make_table(y, z, zs...);
  return vector<decltype(cont)>(x, cont);
}

#define divceil(a, b) ((a) + (b)-1) / (b)
#define is_in(x, a, b) ((a) <= (x) && (x) < (b))
#define uni(x)                                                                 \\
  sort(all(x));                                                                \\
  x.erase(unique(all(x)), x.end())
#define slice(l, r) substr(l, r - l)

typedef long long ll;
typedef long double ld;
using vl = vector<ll>;
using vvl = vector<vl>;
using pll = pair<ll, ll>;

template <typename T> using PQ = priority_queue<T, vector<T>, greater<T>>;
void check_input() {
  assert(cin.eof() == 0);
  int tmp;
  cin >> tmp;
  assert(cin.eof() == 1);
}

#if defined(PCM) || defined(LOCAL)
#else
#define dump(...) ;
#define dump_1d(...) ;
#define dump_2d(...) ;
#define cerrendl ;
#endif

#endif /* HEADER_H */
//%snippet.end()%
#line 2 "solve.cpp"
template <class T = ll> using vec = vector<T>;
struct Fast {
  Fast() {
    std::cin.tie(0);
    ios::sync_with_stdio(false);
  }
} fast;

int solve() {
  ll n;
  cin >> n; /*{{{*/
  vector<ll> a(n + 1);
  ll now = 1;
  rep(i, n + 1) {
    cin >> a[i];
    if (a[i] > now) {
      cout << -1 << endl;
      return 0;
    }
    if (now <= 1e9) {
      now *= 2;
    }
  }

  if (n == 0) {
    if (a[0] == 1) {
      cout << 1 << endl;
      return 0;
    } else {
      cout << -1 << endl;
      return 0;
    }
  } /*}}}*/

  dump(a);
  if (a[0] != 0) {
    cout << -1 << endl;
    return 0;
  }

  vl pu2(n + 1), pd2(n + 1);
  r_rep(i, 0, n) {
    pu2[i] = a[i + 1] + pu2[i + 1];
    pd2[i] = divceil(pd2[i + 1] + a[i + 1], 2);
  }
  dump(pu2);
  dump(pd2);

  vl pu(n + 1), pd(n + 1);
  pu[0] = 1;
  pd[0] = 1;
  rep(i, 1, n + 1) {
    if (pu[i - 1])
      pu[i] = pu[i - 1] * 2 - a[i];
    chmin(pu[i], pu2[i]);
    if (pu[i] < 0) {
      // TODO
      // assert(false);
      cout << -1 << endl;
      return 0;
    }
    pd[i] = max(pd[i - 1] - a[i], 0LL);
  }
  dump(pu);
  dump(pd);

  ll ans = 0;
  rep(i, 0, n + 1) {
    ll d = max(pd[i], pd2[i]);
    ll u = min(pu[i], pu2[i]);
    if (d <= u) {
      ans += u + a[i];
    } else {
      cout << -1 << endl;
      return 0;
    }
  }
  cout << ans << endl;

  return 0;
}

int main() { /*{{{*/
  solve();
  return 0;
} /*}}}*/


Error: 0

Fixed submission:

#line 2 "header.hpp"

//%snippet.set('header')%
//%snippet.fold()%
#ifndef HEADER_H
#define HEADER_H

// template version 2.0
using namespace std;
#include <bits/stdc++.h>

// varibable settings
const long long INF = 1e18;
template <class T> constexpr T inf = numeric_limits<T>::max() / 2.1;

#define _overload3(_1, _2, _3, name, ...) name
#define _rep(i, n) repi(i, 0, n)
#define repi(i, a, b) for (ll i = (ll)(a); i < (ll)(b); ++i)
#define rep(...) _overload3(__VA_ARGS__, repi, _rep, )(__VA_ARGS__)
#define _rrep(i, n) rrepi(i, 0, n)
#define rrepi(i, a, b) for (ll i = (ll)((b)-1); i >= (ll)(a); --i)
#define r_rep(...) _overload3(__VA_ARGS__, rrepi, _rrep, )(__VA_ARGS__)
#define each(i, a) for (auto &&i : a)
#define all(x) (x).begin(), (x).end()
#define sz(x) ((int)(x).size())
#define pb(a) push_back(a)
#define mp(a, b) make_pair(a, b)
#define mt(...) make_tuple(__VA_ARGS__)
#define ub upper_bound
#define lb lower_bound
#define lpos(A, x) (lower_bound(all(A), x) - A.begin())
#define upos(A, x) (upper_bound(all(A), x) - A.begin())
template <class T> inline void chmax(T &a, const T &b) {
  if ((a) < (b))
    (a) = (b);
}
template <class T> inline void chmin(T &a, const T &b) {
  if ((a) > (b))
    (a) = (b);
}
template <typename X, typename T> auto make_table(X x, T a) {
  return vector<T>(x, a);
}
template <typename X, typename Y, typename Z, typename... Zs>
auto make_table(X x, Y y, Z z, Zs... zs) {
  auto cont = make_table(y, z, zs...);
  return vector<decltype(cont)>(x, cont);
}

#define divceil(a, b) ((a) + (b)-1) / (b)
#define is_in(x, a, b) ((a) <= (x) && (x) < (b))
#define uni(x)                                                                 \\
  sort(all(x));                                                                \\
  x.erase(unique(all(x)), x.end())
#define slice(l, r) substr(l, r - l)

typedef long long ll;
typedef long double ld;
using vl = vector<ll>;
using vvl = vector<vl>;
using pll = pair<ll, ll>;

template <typename T> using PQ = priority_queue<T, vector<T>, greater<T>>;
void check_input() {
  assert(cin.eof() == 0);
  int tmp;
  cin >> tmp;
  assert(cin.eof() == 1);
}

#if defined(PCM) || defined(LOCAL)
#else
#define dump(...) ;
#define dump_1d(...) ;
#define dump_2d(...) ;
#define cerrendl ;
#endif

#endif /* HEADER_H */
//%snippet.end()%
#line 2 "solve.cpp"
template <class T = ll> using vec = vector<T>;
struct Fast {
  Fast() {
    std::cin.tie(0);
    ios::sync_with_stdio(false);
  }
} fast;

int solve() {
  ll n;
  cin >> n; /*{{{*/
  vector<ll> a(n + 1);
  ll now = 1;
  rep(i, n + 1) {
    cin >> a[i];
    if (a[i] > now) {
      cout << -1 << endl;
      return 0;
    }
    if (now <= 1e9) {
      now *= 2;
    }
  }

  if (n == 0) {
    if (a[0] == 1) {
      cout << 1 << endl;
      return 0;
    } else {
      cout << -1 << endl;
      return 0;
    }
  } /*}}}*/

  dump(a);
  if (a[0] != 0) {
    cout << -1 << endl;
    return 0;
  }

  vl pu(n + 1), pd(n + 1);
  pu[0] = 1;
  pd[0] = 1;
  rep(i, 1, n + 1) {
    pu[i] = pu[i - 1] * 2 - a[i];
    if (pu[i] < 0) {
      // TODO
      assert(false);
      cout << -1 << endl;
      return 0;
    }
    pd[i] = max(pd[i - 1] - a[i], 0LL);
  }
  dump(pu);
  dump(pd);

  vl pu2(n + 1), pd2(n + 1);
  r_rep(i, 0, n) {
    pu2[i] = a[i + 1] + pu2[i + 1];
    pd2[i] = divceil(pd2[i + 1] + a[i + 1], 2);
  }
  dump(pu2);
  dump(pd2);

  ll ans = 0;
  rep(i, 0, n + 1) {
    ll d = max(pd[i], pd2[i]);
    ll u = min(pu[i], pu2[i]);
    if (d <= u) {
      ans += u + a[i];
    } else {
      cout << -1 << endl;
      return 0;
    }
  }
  cout << ans << endl;

  return 0;
}

int main() { /*{{{*/
  solve();
  return 0;
} /*}}}*/