Problem p02616 (C++) — buggy submission, verdict: Runtime Error

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

#define li long long int
#define rep(i, to) for (li i = 0; i < ((li)(to)); i++)
#define repp(i, start, to) for (li i = (li)(start); i < ((li)(to)); i++)
#define pb push_back
#define sz(v) ((li)(v).size())
#define bgn(v) ((v).begin())
#define eend(v) ((v).end())
#define allof(v) (v).begin(), (v).end()
#define dodp(v, n) memset(v, (li)n, sizeof(v))
#define bit(n) (1ll << (li)(n))
#define mp(a, b) make_pair(a, b)
#define rin rep(i, n)
#define EPS 1e-12
#define ETOL 1e-8
#define MOD 1000000007
typedef pair<li, li> PI;

#define INF bit(60)

#define DBGP 1

#define idp if (DBGP)
#define F first
#define S second
#define p2(a, b) idp cout << a << "\\t" << b << endl
#define p3(a, b, c) idp cout << a << "\\t" << b << "\\t" << c << endl
#define p4(a, b, c, d)                                                         \\
  idp cout << a << "\\t" << b << "\\t" << c << "\\t" << d << endl
#define p5(a, b, c, d, e)                                                      \\
  idp cout << a << "\\t" << b << "\\t" << c << "\\t" << d << "\\t" << e << endl
#define p6(a, b, c, d, e, f)                                                   \\
  idp cout << a << "\\t" << b << "\\t" << c << "\\t" << d << "\\t" << e << "\\t"    \\
           << f << endl
#define p7(a, b, c, d, e, f, g)                                                \\
  idp cout << a << "\\t" << b << "\\t" << c << "\\t" << d << "\\t" << e << "\\t"    \\
           << f << "\\t" << g << endl
#define p8(a, b, c, d, e, f, g, h)                                             \\
  idp cout << a << "\\t" << b << "\\t" << c << "\\t" << d << "\\t" << e << "\\t"    \\
           << f << "\\t" << g << "\\t" << h << endl
#define p9(a, b, c, d, e, f, g, h, i)                                          \\
  idp cout << a << "\\t" << b << "\\t" << c << "\\t" << d << "\\t" << e << "\\t"    \\
           << f << "\\t" << g << "\\t" << h << "\\t" << i << endl
#define p10(a, b, c, d, e, f, g, h, i, j)                                      \\
  idp cout << a << "\\t" << b << "\\t" << c << "\\t" << d << "\\t" << e << "\\t"    \\
           << f << "\\t" << g << "\\t" << h << "\\t" << i << "\\t" << j << endl
#define foreach(it, v)                                                         \\
  for (__typeof((v).begin()) it = (v).begin(); it != (v).end(); ++it)
#define p2p(x) idp p2((x).F, (x).S)
#define dump(x, n)                                                             \\
  idp {                                                                        \\
    rep(i, n) { cout << x[i] << " "; }                                         \\
    puts("");                                                                  \\
  }
#define dump2(x, n)                                                            \\
  idp {                                                                        \\
    rep(i, n) { cout << "[" << x[i].F << " , " << x[i].S << "] "; }            \\
    puts("");                                                                  \\
  }
#define dumpi(x)                                                               \\
  idp {                                                                        \\
    foreach (it, x) {                                                          \\
      cout << (*it) << " ";                                                    \\
    }                                                                          \\
    puts("");                                                                  \\
  }
#define dumpi2(x)                                                              \\
  idp {                                                                        \\
    foreach (it, x) {                                                          \\
      cout << "[" << (it)->F << " , " << (it)->S << "] ";                      \\
    }                                                                          \\
    puts("");                                                                  \\
  }

#define read2d(a, w, h) rep(i, h) rep(j, w) cin >> a[i][j]
#define dump2d(a, w, h)                                                        \\
  rep(i, h) {                                                                  \\
    rep(j, w) cout << a[i][j] << " ";                                          \\
    puts("");                                                                  \\
  }

typedef pair<li, li> PI;

li n, k;
li a[200200];

inline li calc(vector<li> &v) {
  li res = 1;
  for (auto vv : v) {
    res = (res * vv) % MOD;
  }
  return (res + MOD) % MOD;
}

int main() {
  vector<PI> pn;

  cin >> n;
  cin >> k;
  li cz = 0;
  rin {
    cin >> a[i];
    if (a[i] == 0) {
      cz++;
      pn.pb({0, 0});
    } else {
      pn.pb({abs(a[i]), a[i] / abs(a[i])});
    }
  }
  if (n - cz < k) {
    cout << 0 << endl;
    return 0;
  }
  if (n == k) {
    vector<li> v;
    rin { v.pb(a[i]); }
    cout << calc(v) << endl;
    return 0;
  }

  sort(allof(pn));
  vector<li> pos;
  vector<li> neg;
  rep(i, k) {
    if (pn[n - 1 - i].S > 0) {
      pos.pb(pn[n - 1 - i].F);
    } else if (pn[n - 1 - i].S < 0) {
      neg.pb(pn[n - 1 - i].F);
    }
  }
  li next_pos = -1;
  li next_neg = -1;
  repp(i, k, n) {
    if (pn[n - 1 - i].S > 0) {
      next_pos = max(next_pos, pn[n - 1 - i].F);
    } else if (pn[n - 1 - i].S < 0) {
      next_neg = max(next_neg, pn[n - 1 - i].F);
    }
  }

  if (sz(neg) % 2 > 0) {
    if (pos.empty()) {
      if (next_pos < 0) {
        // only neg and k=odd
        if (cz > 0) {
          cout << 0 << endl;
          return 0;
        }
        vector<li> v;
        rin {
          if (a[i] < 0) {
            v.pb(a[i]);
          }
        }
        sort(allof(v));
        reverse(allof(v));
        v.resize(k);
        cout << calc(v) << endl;
        return 0;
      } else {
        neg.pop_back();
        pos.pb(next_pos);
      }
    } else if (next_pos < 0) {
      if (next_neg < 0) {
        cout << 0 << endl;
        return 0;
      }
      // increace neg
      pos.pop_back();
      neg.pb(next_neg);
    } else if (next_neg < 0) {
      // increace pos
      neg.pop_back();
      pos.pb(next_pos);
    } else {
      // select better
      li pos_mul = pos.back() * next_pos;
      li neg_mul = neg.back() * next_neg;
      if (pos_mul > neg_mul) {
        neg.pop_back();
        pos.pb(next_pos);
      } else {
        pos.pop_back();
        neg.pb(next_neg);
      }
    }
  }
  vector<li> res;
  res.insert(res.end(), allof(pos));
  res.insert(res.end(), allof(neg));

  cout << calc(res) << endl;

  return 0;
}

Error: 0

Fixed submission:

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

#define li long long int
#define rep(i, to) for (li i = 0; i < ((li)(to)); i++)
#define repp(i, start, to) for (li i = (li)(start); i < ((li)(to)); i++)
#define pb push_back
#define sz(v) ((li)(v).size())
#define bgn(v) ((v).begin())
#define eend(v) ((v).end())
#define allof(v) (v).begin(), (v).end()
#define dodp(v, n) memset(v, (li)n, sizeof(v))
#define bit(n) (1ll << (li)(n))
#define mp(a, b) make_pair(a, b)
#define rin rep(i, n)
#define EPS 1e-12
#define ETOL 1e-8
#define MOD 1000000007
typedef pair<li, li> PI;

#define INF bit(60)

#define DBGP 1

#define idp if (DBGP)
#define F first
#define S second
#define p2(a, b) idp cout << a << "\\t" << b << endl
#define p3(a, b, c) idp cout << a << "\\t" << b << "\\t" << c << endl
#define p4(a, b, c, d)                                                         \\
  idp cout << a << "\\t" << b << "\\t" << c << "\\t" << d << endl
#define p5(a, b, c, d, e)                                                      \\
  idp cout << a << "\\t" << b << "\\t" << c << "\\t" << d << "\\t" << e << endl
#define p6(a, b, c, d, e, f)                                                   \\
  idp cout << a << "\\t" << b << "\\t" << c << "\\t" << d << "\\t" << e << "\\t"    \\
           << f << endl
#define p7(a, b, c, d, e, f, g)                                                \\
  idp cout << a << "\\t" << b << "\\t" << c << "\\t" << d << "\\t" << e << "\\t"    \\
           << f << "\\t" << g << endl
#define p8(a, b, c, d, e, f, g, h)                                             \\
  idp cout << a << "\\t" << b << "\\t" << c << "\\t" << d << "\\t" << e << "\\t"    \\
           << f << "\\t" << g << "\\t" << h << endl
#define p9(a, b, c, d, e, f, g, h, i)                                          \\
  idp cout << a << "\\t" << b << "\\t" << c << "\\t" << d << "\\t" << e << "\\t"    \\
           << f << "\\t" << g << "\\t" << h << "\\t" << i << endl
#define p10(a, b, c, d, e, f, g, h, i, j)                                      \\
  idp cout << a << "\\t" << b << "\\t" << c << "\\t" << d << "\\t" << e << "\\t"    \\
           << f << "\\t" << g << "\\t" << h << "\\t" << i << "\\t" << j << endl
#define foreach(it, v)                                                         \\
  for (__typeof((v).begin()) it = (v).begin(); it != (v).end(); ++it)
#define p2p(x) idp p2((x).F, (x).S)
#define dump(x, n)                                                             \\
  idp {                                                                        \\
    rep(i, n) { cout << x[i] << " "; }                                         \\
    puts("");                                                                  \\
  }
#define dump2(x, n)                                                            \\
  idp {                                                                        \\
    rep(i, n) { cout << "[" << x[i].F << " , " << x[i].S << "] "; }            \\
    puts("");                                                                  \\
  }
#define dumpi(x)                                                               \\
  idp {                                                                        \\
    foreach (it, x) {                                                          \\
      cout << (*it) << " ";                                                    \\
    }                                                                          \\
    puts("");                                                                  \\
  }
#define dumpi2(x)                                                              \\
  idp {                                                                        \\
    foreach (it, x) {                                                          \\
      cout << "[" << (it)->F << " , " << (it)->S << "] ";                      \\
    }                                                                          \\
    puts("");                                                                  \\
  }

#define read2d(a, w, h) rep(i, h) rep(j, w) cin >> a[i][j]
#define dump2d(a, w, h)                                                        \\
  rep(i, h) {                                                                  \\
    rep(j, w) cout << a[i][j] << " ";                                          \\
    puts("");                                                                  \\
  }

typedef pair<li, li> PI;

li n, k;
li a[200200];

inline li calc(vector<li> &v) {
  li res = 1;
  for (auto vv : v) {
    res = (res * vv) % MOD;
  }
  return (res + MOD) % MOD;
}

int main() {
  vector<PI> pn;

  cin >> n;
  cin >> k;
  li cz = 0;
  rin {
    cin >> a[i];
    if (a[i] == 0) {
      cz++;
    } else {
      pn.pb({abs(a[i]), a[i] / abs(a[i])});
    }
  }
  if (n - cz < k) {
    cout << 0 << endl;
    return 0;
  }
  if (n == k) {
    vector<li> v;
    rin { v.pb(a[i]); }
    cout << calc(v) << endl;
    return 0;
  }

  sort(allof(pn));
  li last_pos = INF;
  li last_neg = INF;
  vector<li> pos;
  vector<li> neg;
  rep(i, k) {
    if (pn[n - 1 - i].S > 0) {
      pos.pb(pn[n - 1 - i].F);
    } else {
      neg.pb(pn[n - 1 - i].F);
    }
  }
  li next_pos = -1;
  li next_neg = -1;
  repp(i, k, n) {
    if (pn[n - 1 - i].S > 0) {
      next_pos = max(next_pos, pn[n - 1 - i].F);
    } else {
      next_neg = max(next_neg, pn[n - 1 - i].F);
    }
  }

  if (sz(neg) % 2 > 0) {
    if (pos.empty()) {
      if (next_pos < 0) {
        // only neg and k=odd
        vector<li> v;
        rin {
          if (a[i] < 0) {
            v.pb(a[i]);
          }
        }
        v.resize(k);
        cout << calc(v) << endl;
        return 0;
      } else {
        neg.pop_back();
        pos.pb(next_pos);
      }
    } else if (next_pos < 0) {
      // increace neg
      pos.pop_back();
      neg.pb(next_neg);
    } else if (next_neg < 0) {
      // increace pos
      neg.pop_back();
      pos.pb(next_pos);
    } else {
      // select better
      li pos_mul = pos.back() * next_pos;
      li neg_mul = neg.back() * next_neg;
      if (pos_mul > neg_mul) {
        neg.pop_back();
        pos.pb(next_pos);
      } else {
        pos.pop_back();
        neg.pb(next_neg);
      }
    }
  }
  vector<li> res;
  res.insert(res.end(), allof(pos));
  res.insert(res.end(), allof(neg));

  cout << calc(res) << endl;

  return 0;
}