Problem p00202 (C++) — buggy submission, verdict: Memory Limit Exceeded

#include <bits/stdc++.h>
using namespace std;
#define FOR(i, s, n) for (int i = s; i < (int)n; i++)
#define per(i, n) for (int i = n; i >= 0; i--)
#define ROF(i, s, n) for (int i = s; i >= (int)n; i--)
#define FORIT(i, A) for (auto i : A)
#define PRINT(x) cout << (x) << "\\n"
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define MP make_pair
#define EACH(i, n)                                                             \\
  for (__typeof((n).begin()) i = (n).begin(); i != (n).end(); ++i)
#define SZ(a) int((a).size())
#define EXIST(s, e) ((s).find(e) != (s).end())
#define SORT(c) sort((c).begin(), (c).end())
#define CLR(a) memset((a), 0, sizeof(a))
#define NCLR(a) memset((a), -1, sizeof(a))
#define dump(x) cout << #x << " = " << (x) << "\\n";
#define debug(x)                                                               \\
  cout << #x << " = " << (x) << " (L" << __LINE__ << ")"                       \\
       << " " << __FILE__ << "\\n";
#define sq(n) (n) * (n)
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef long long LL;
typedef vector<LL> VLL;
typedef vector<VLL> VVLL;
typedef unsigned int uint;
typedef unsigned long long ull;
typedef priority_queue<int> maxpq;
typedef priority_queue<int, vector<int>, greater<int>> minpq;
static const double EPS = 1e-10;
static const double PI = acos(-1.0);
static const int mod = 1000000007;
static const int INF = 1 << 25;
static const LL LL_INF = 1152921504606846976;
static const int dx[] = {-1, 0, 1, 0, 1, -1, 1, -1};
static const int dy[] = {0, -1, 0, 1, 1, 1, -1, -1};

static int dp[1000001];
static bool is_pm[1000001];
static int n, m;
static VI _array;

int solve(int now, int many) {
  if (dp[many] >= 0) {
    return dp[many];
  }
  if (now == n) {
    if (is_pm[many]) {
      return dp[many] = many;
    }
    return dp[many] = 0;
  }
  int res = 0;
  for (int i = 0; many + _array[now] * i <= m; i++) {
    res = max(res, solve(now + 1, many + _array[now] * i));
  }
  return dp[many] = res;
}

int main() {
  NCLR(is_pm);
  for (int i = 2; sq(i) <= 1000000; i += 2) {
    if (is_pm[i]) {
      for (int j = i * i; j <= 1000000; j += i) {
        is_pm[j] = false;
        if (i != 2) {
          j += i;
        }
      }
    }
    if (i == 2) {
      --i;
    }
  }
  is_pm[0] = is_pm[1] = false;
  while (~scanf("%d %d", &n, &m) && n && m) {
    _array.resize(n);
    for (int i = 0; i < n; i++) {
      scanf("%d", &_array[i]);
    }
    sort(_array.rbegin(), _array.rend());
    _array.erase(unique(_array.begin(), _array.end()), _array.end());
    n = _array.size();
    NCLR(dp);
    int ans = solve(0, 0);
    if (ans) {
      printf("%d\\n", ans);
    } else {
      printf("NA\\n");
    }
  }
  return 0;
}

Error: MLE

Fixed submission:

#include <bits/stdc++.h>
using namespace std;
#define FOR(i, s, n) for (int i = s; i < (int)n; i++)
#define per(i, n) for (int i = n; i >= 0; i--)
#define ROF(i, s, n) for (int i = s; i >= (int)n; i--)
#define FORIT(i, A) for (auto i : A)
#define PRINT(x) cout << (x) << "\\n"
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define MP make_pair
#define EACH(i, n)                                                             \\
  for (__typeof((n).begin()) i = (n).begin(); i != (n).end(); ++i)
#define SZ(a) int((a).size())
#define EXIST(s, e) ((s).find(e) != (s).end())
#define SORT(c) sort((c).begin(), (c).end())
#define CLR(a) memset((a), 0, sizeof(a))
#define NCLR(a) memset((a), -1, sizeof(a))
#define dump(x) cout << #x << " = " << (x) << "\\n";
#define debug(x)                                                               \\
  cout << #x << " = " << (x) << " (L" << __LINE__ << ")"                       \\
       << " " << __FILE__ << "\\n";
#define sq(n) (n) * (n)
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef long long LL;
typedef vector<LL> VLL;
typedef vector<VLL> VVLL;
typedef unsigned int uint;
typedef unsigned long long ull;
typedef priority_queue<int> maxpq;
typedef priority_queue<int, vector<int>, greater<int>> minpq;
static const double EPS = 1e-10;
static const double PI = acos(-1.0);
static const int mod = 1000000007;
static const int INF = 1 << 25;
static const LL LL_INF = 1152921504606846976;
static const int dx[] = {-1, 0, 1, 0, 1, -1, 1, -1};
static const int dy[] = {0, -1, 0, 1, 1, 1, -1, -1};

static int dp[31][1000001];
static bool is_pm[1000001];
static int n, m;
static VI _array;

int solve(int now, int many) {
  if (dp[now][many] >= 0) {
    return dp[now][many];
  }
  if (now == n) {
    if (is_pm[many]) {
      return dp[now][many] = many;
    }
    return dp[now][many] = 0;
  }
  int res = 0;
  for (int i = 0; many + _array[now] * i <= m; i++) {
    res = max(res, solve(now + 1, many + _array[now] * i));
  }
  return dp[now][many] = res;
}

int main() {
  NCLR(is_pm);
  for (int i = 2; sq(i) <= 1000000; i += 2) {
    if (is_pm[i]) {
      for (int j = i * i; j <= 1000000; j += i) {
        is_pm[j] = false;
        if (i != 2) {
          j += i;
        }
      }
    }
    if (i == 2) {
      --i;
    }
  }
  is_pm[0] = is_pm[1] = false;
  while (~scanf("%d %d", &n, &m) && n && m) {
    _array.resize(n);
    for (int i = 0; i < n; i++) {
      scanf("%d", &_array[i]);
    }
    sort(_array.rbegin(), _array.rend());
    _array.erase(unique(_array.begin(), _array.end()), _array.end());
    n = _array.size();
    NCLR(dp);
    int ans = solve(0, 0);
    if (ans) {
      printf("%d\\n", ans);
    } else {
      printf("NA\\n");
    }
  }
  return 0;
}