Problem p03780 (C++)

Buggy submission (status: Runtime Error):
#include <algorithm>
#include <bitset>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>
#define _USE_MATH_DEFINES
#include <math.h>

using namespace std;

inline int toInt(string s) {
  int v;
  istringstream sin(s);
  sin >> v;
  return v;
}
template <class T> inline string toString(T x) {
  ostringstream sout;
  sout << x;
  return sout.str();
}

template <class T> inline T sqr(T x) { return x * x; }

typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<long long int> vll;
typedef vector<string> vs;
typedef pair<int, int> pii;
typedef long long ll;
typedef unsigned long long ull;

// repetition
//------------------------------------------
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define rep(i, n) FOR(i, 0, n)
#define P(p) cout << (p) << endl;
#define VEC_2D(a, b) vector<vector<int>>(a, vector<int>(b, 0))
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define pb push_back
#define mp make_pair
#define INF (1100000000)
#define SZ(a) int((a).size())
#define EACH(i, c)                                                             \
  for (typeof((c).begin()) i = (c).begin(); i != (c).end(); ++i)
#define EXIST(s, e) ((s).find(e) != (s).end())
#define SORT(c) sort((c).begin(), (c).end())
#define MOD 1000000007LL
#define FSP(a) cout << fixed << setprecision(a)

ll gcd(ll x, ll y) {
  if (y == 0)
    return x;
  else
    return gcd(y, x % y);
}
ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }
bool is_prime(int n) {
  for (int i = 2; i * i <= n; i++) {
    if (n % i == 0)
      return false;
  }
  return n != 1;
}
map<int, int> prime_factor(int n) {
  map<int, int> res;
  for (int i = 2; i * i <= n; i++) {
    while (n % i == 0) {
      ++res[i];
      n /= i;
    }
  }
  if (n != 1)
    res[n] = 1;
  return res;
}
int extgcd(int a, int b, int &x, int &y) { //
  int d = a;
  if (b != 0) {
    d = extgcd(b, a % b, y, x);
    y -= (a / b) * x;
  } else {
    x = 1;
    y = 0;
  }
  return d;
}

ll mod_pow(ll x, ll n, ll mod) {
  if (n == 0)
    return 1;
  ll res = mod_pow(x * x % mod, n / 2, mod);
  if (n & 1)
    res = res * x % mod;
  return res;
}
vector<string> split(const string &str, char delim) {
  vector<string> res;
  size_t current = 0, found;
  while ((found = str.find_first_of(delim, current)) != string::npos) {
    res.push_back(string(str, current, found - current));
    current = found + 1;
  }
  res.push_back(string(str, current, str.size() - current));
  return res;
}

bool is_kadomatsu(int a, int b, int c) {
  if (a == b || a == c || b == c)
    return false;
  if (a > b && c > b)
    return true;
  if (a < b && c < b)
    return true;
  return false;
}

struct UF {
  int n;
  vi d;
  UF() {}
  UF(int n) : n(n), d(n, -1) {}
  int root(int v) {
    if (d[v] < 0)
      return v;
    return d[v] = root(d[v]);
  }
  bool unite(int x, int y) {
    x = root(x);
    y = root(y);
    if (x == y)
      return false;
    if (size(x) < size(y))
      swap(x, y);
    d[x] += d[y];
    d[y] = x;
    return true;
  }
  int size(int v) { return -d[root(v)]; }
};

vector<int> divisor(int n) {
  if (n == 1)
    return {};
  vi res;
  for (int i = 1; i * i <= n; i++) {
    if (n % i == 0) {
      res.emplace_back(i);
      if (i != 1 && i != n / i)
        res.emplace_back(n / i);
    }
  }
  return res;
}
//-------------------------------------------------------------

int n, k;
vi a;

bool huyou(int t) {
  bool ok[50][50];
  memset(ok, 0, sizeof(ok));
  ok[0][0] = true;
  rep(i, n) {
    rep(j, k) {
      if (i == t) {
        ok[i + 1][j] = ok[i][j];
      } else {
        if (ok[i][j]) {
          ok[i + 1][j] = true;
        }
        if (ok[i][j] && j + a[i] < k) {
          ok[i + 1][j + a[i]] = true;
        }
      }
    }
  }
  /*P(t);
  rep(i, n+1) {
          rep(j, k) {
                  cout << ok[i][j] << " ";
          }
          cout << endl;
  }*/
  for (int j = k - a[t]; j < k; j++) {
    if (ok[n][j]) {
      return false;
    }
  }
  return true;
}
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cin >> n >> k;
  a.resize(n);
  rep(i, n) cin >> a[i];
  sort(ALL(a));
  if (a[0] >= k) {
    P(0);
  } else {
    int l = -1, r = n;
    while (r - l > 1) {
      int mid = (r + l) / 2;
      if (a[mid] < k && huyou(mid)) {
        l = mid;
      } else {
        r = mid;
      }
    }
    P(l + 1);
  }

  return 0;
}

Fixed submission:
#include <algorithm>
#include <bitset>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>
#define _USE_MATH_DEFINES
#include <math.h>

using namespace std;

inline int toInt(string s) {
  int v;
  istringstream sin(s);
  sin >> v;
  return v;
}
template <class T> inline string toString(T x) {
  ostringstream sout;
  sout << x;
  return sout.str();
}

template <class T> inline T sqr(T x) { return x * x; }

typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<long long int> vll;
typedef vector<string> vs;
typedef pair<int, int> pii;
typedef long long ll;
typedef unsigned long long ull;

// repetition
//------------------------------------------
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define rep(i, n) FOR(i, 0, n)
#define P(p) cout << (p) << endl;
#define VEC_2D(a, b) vector<vector<int>>(a, vector<int>(b, 0))
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define pb push_back
#define mp make_pair
#define INF (1100000000)
#define SZ(a) int((a).size())
#define EACH(i, c)                                                             \
  for (typeof((c).begin()) i = (c).begin(); i != (c).end(); ++i)
#define EXIST(s, e) ((s).find(e) != (s).end())
#define SORT(c) sort((c).begin(), (c).end())
#define MOD 1000000007LL
#define FSP(a) cout << fixed << setprecision(a)

ll gcd(ll x, ll y) {
  if (y == 0)
    return x;
  else
    return gcd(y, x % y);
}
ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }
bool is_prime(int n) {
  for (int i = 2; i * i <= n; i++) {
    if (n % i == 0)
      return false;
  }
  return n != 1;
}
map<int, int> prime_factor(int n) {
  map<int, int> res;
  for (int i = 2; i * i <= n; i++) {
    while (n % i == 0) {
      ++res[i];
      n /= i;
    }
  }
  if (n != 1)
    res[n] = 1;
  return res;
}
int extgcd(int a, int b, int &x, int &y) { //
  int d = a;
  if (b != 0) {
    d = extgcd(b, a % b, y, x);
    y -= (a / b) * x;
  } else {
    x = 1;
    y = 0;
  }
  return d;
}

ll mod_pow(ll x, ll n, ll mod) {
  if (n == 0)
    return 1;
  ll res = mod_pow(x * x % mod, n / 2, mod);
  if (n & 1)
    res = res * x % mod;
  return res;
}
vector<string> split(const string &str, char delim) {
  vector<string> res;
  size_t current = 0, found;
  while ((found = str.find_first_of(delim, current)) != string::npos) {
    res.push_back(string(str, current, found - current));
    current = found + 1;
  }
  res.push_back(string(str, current, str.size() - current));
  return res;
}

bool is_kadomatsu(int a, int b, int c) {
  if (a == b || a == c || b == c)
    return false;
  if (a > b && c > b)
    return true;
  if (a < b && c < b)
    return true;
  return false;
}

struct UF {
  int n;
  vi d;
  UF() {}
  UF(int n) : n(n), d(n, -1) {}
  int root(int v) {
    if (d[v] < 0)
      return v;
    return d[v] = root(d[v]);
  }
  bool unite(int x, int y) {
    x = root(x);
    y = root(y);
    if (x == y)
      return false;
    if (size(x) < size(y))
      swap(x, y);
    d[x] += d[y];
    d[y] = x;
    return true;
  }
  int size(int v) { return -d[root(v)]; }
};

vector<int> divisor(int n) {
  if (n == 1)
    return {};
  vi res;
  for (int i = 1; i * i <= n; i++) {
    if (n % i == 0) {
      res.emplace_back(i);
      if (i != 1 && i != n / i)
        res.emplace_back(n / i);
    }
  }
  return res;
}
//-------------------------------------------------------------

int n, k;
vi a;

bool huyou(int t) {
  bool ok[5010][5010];
  memset(ok, 0, sizeof(ok));
  ok[0][0] = true;
  rep(i, n) {
    rep(j, k) {
      if (i == t) {
        ok[i + 1][j] = ok[i][j];
      } else {
        if (ok[i][j]) {
          ok[i + 1][j] = true;
        }
        if (ok[i][j] && j + a[i] < k) {
          ok[i + 1][j + a[i]] = true;
        }
      }
    }
  }
  /*P(t);
  rep(i, n+1) {
          rep(j, k) {
                  cout << ok[i][j] << " ";
          }
          cout << endl;
  }*/
  for (int j = k - a[t]; j < k; j++) {
    if (ok[n][j]) {
      return false;
    }
  }
  return true;
}
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cin >> n >> k;
  a.resize(n);
  rep(i, n) cin >> a[i];
  sort(ALL(a));
  if (a[0] >= k) {
    P(0);
  } else {
    int l = -1, r = n;
    while (r - l > 1) {
      int mid = (r + l) / 2;
      if (a[mid] < k && huyou(mid)) {
        l = mid;
      } else {
        r = mid;
      }
    }
    P(l + 1);
  }

  return 0;
}