Problem p00922 (C++) — buggy submission, verdict: Runtime Error

#include <bits/stdc++.h>

#define _overload(_1, _2, _3, name, ...) name
#define _rep(i, n) _range(i, 0, n)
#define _range(i, a, b) for (int i = int(a); i < int(b); ++i)
#define rep(...) _overload(__VA_ARGS__, _range, _rep, )(__VA_ARGS__)

#define _rrep(i, n) _rrange(i, n, 0)
#define _rrange(i, a, b) for (int i = int(a) - 1; i >= int(b); --i)
#define rrep(...) _overload(__VA_ARGS__, _rrange, _rrep, )(__VA_ARGS__)

#define _all(arg) begin(arg), end(arg)
#define uniq(arg) sort(_all(arg)), (arg).erase(unique(_all(arg)), end(arg))
#define getidx(ary, key) lower_bound(_all(ary), key) - begin(ary)
#define clr(a, b) memset((a), (b), sizeof(a))
#define bit(n) (1LL << (n))
#define popcount(n) (__builtin_popcountll(n))

using namespace std;

template <class T> bool chmax(T &a, const T &b) {
  return (a < b) ? (a = b, 1) : 0;
}
template <class T> bool chmin(T &a, const T &b) {
  return (b < a) ? (a = b, 1) : 0;
}

using ll = long long;
using R = long double;
const R EPS = 1e-9; // [-1000,1000]->EPS=1e-8 [-10000,10000]->EPS=1e-7
inline int sgn(const R &r) { return (r > EPS) - (r < -EPS); }
inline R sq(R x) { return sqrt(max<R>(x, 0.0)); }

const int dx[8] = {1, 0, -1, 0, 1, -1, -1, 1};
const int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};

// Problem Specific Parameter:
const int sz = 1 << 19;
int dp[2][sz];
bool ok[2][sz];

int calc(const vector<int> &a) {
  const int n = a.size();
  int limit = 0;
  ok[0][0] = true;

  rep(i, n) {
    int cur = i & 1, nxt = cur ^ 1, nlimit = limit;
    rep(j, limit + 1) {
      if (ok[cur][j] == false)
        continue;
      chmax(dp[nxt][j], dp[cur][j]), ok[nxt][j] = true;
      if (j % a[i] == 0) {
        ok[nxt][j + a[i]] = true;
        chmax(dp[nxt][j + a[i]], dp[cur][j] + 1);
        chmax(nlimit, j + a[i]);
      }
    }
    rep(j, limit + 1) dp[cur][j] = 0, ok[cur][j] = false;
    limit = nlimit;
  }

  int cmax = 0;
  rep(j, 20) if ((1 << j) <= limit) chmax(cmax, dp[n & 1][1 << j]);

  // cout << cmax << endl;
  // if(cmax==516) rep(j,20) cout << dp[n&1][1<<j] << endl;

  rep(i, 2) rep(j, limit + 1) dp[i][j] = 0, ok[i][j] = false;
  return cmax;
}

int main(void) {
  int n;
  while (cin >> n, n) {
    vector<int> a(n);
    rep(i, n) cin >> a[i];
    int ans = 1;
    rep(small, 1, 501) {
      if (small % 2 == 0)
        continue;
      vector<int> b;
      rep(i, n) if (small <= a[i] and a[i] % small == 0 and
                    __builtin_popcount(a[i] / small) == 1)
          b.push_back(a[i] / small);
      chmax(ans, calc(b));
    }
    cout << ans << endl;
  }
  return 0;
}

Error: 0

Fixed submission:

#include <bits/stdc++.h>

#define _overload(_1, _2, _3, name, ...) name
#define _rep(i, n) _range(i, 0, n)
#define _range(i, a, b) for (int i = int(a); i < int(b); ++i)
#define rep(...) _overload(__VA_ARGS__, _range, _rep, )(__VA_ARGS__)

#define _rrep(i, n) _rrange(i, n, 0)
#define _rrange(i, a, b) for (int i = int(a) - 1; i >= int(b); --i)
#define rrep(...) _overload(__VA_ARGS__, _rrange, _rrep, )(__VA_ARGS__)

#define _all(arg) begin(arg), end(arg)
#define uniq(arg) sort(_all(arg)), (arg).erase(unique(_all(arg)), end(arg))
#define getidx(ary, key) lower_bound(_all(ary), key) - begin(ary)
#define clr(a, b) memset((a), (b), sizeof(a))
#define bit(n) (1LL << (n))
#define popcount(n) (__builtin_popcountll(n))

using namespace std;

template <class T> bool chmax(T &a, const T &b) {
  return (a < b) ? (a = b, 1) : 0;
}
template <class T> bool chmin(T &a, const T &b) {
  return (b < a) ? (a = b, 1) : 0;
}

using ll = long long;
using R = long double;
const R EPS = 1e-9; // [-1000,1000]->EPS=1e-8 [-10000,10000]->EPS=1e-7
inline int sgn(const R &r) { return (r > EPS) - (r < -EPS); }
inline R sq(R x) { return sqrt(max<R>(x, 0.0)); }

const int dx[8] = {1, 0, -1, 0, 1, -1, -1, 1};
const int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};

// Problem Specific Parameter:
const int sz = 122000;
int dp[2][sz];

int calc(const vector<int> &a) {
  const int n = a.size();
  rep(i, 2) rep(j, sz) dp[i][j] = 0;
  int limit = 0;

  rep(i, n) {
    int cur = i & 1, nxt = cur ^ 1, nlimit = limit;
    rep(j, limit + 1) {
      chmax(dp[nxt][j], dp[cur][j]);
      if (j % a[i] == 0)
        chmax(dp[nxt][j + a[i]], dp[cur][j] + 1), chmax(nlimit, j + a[i]);
    }
    rep(j, limit + 1) dp[cur][j] = 0;
    limit = nlimit;
  }

  int cmax = 0;
  rep(j, 20) if ((1 << j) <= limit) chmax(cmax, dp[n & 1][1 << j]);
  return cmax;
}

int main(void) {
  int n;
  while (cin >> n, n) {
    vector<int> a(n);
    rep(i, n) cin >> a[i];
    int ans = 1;
    rep(small, 1, 501) {
      if (small % 2 == 0)
        continue;
      vector<int> b;
      rep(i, n) if (small <= a[i] and a[i] % small == 0 and
                    __builtin_popcount(a[i] / small) == 1)
          b.push_back(a[i] / small);
      chmax(ans, calc(b));
    }
    cout << ans << endl;
  }
  return 0;
}