big data kattis

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

#define LSOne(a) ((a) & -(a))
typedef vector< int > vi;
#define OO int(1e9)

const int N = 15;

int numDiffPF[15000]; // num of distinct primes
int memo[N][1 << N];
int n ,a[N];

void modified_sieve(int upperbound)
{
    for(int i = 2 ; i < upperbound ; i++)
        if( !numDiffPF[i] )
            for(int j = i ; j < upperbound ; j += i)
                numDiffPF[j] += 1;
}

int calc(int i ,int Mask)
{
    if( i == n ) return !Mask ? 0 : -OO;

    int &re = memo[i][Mask];
    if( re + 1 ) return re;

    /// --- Pruning The DP A Bit --- ///
        /// --- store the valid elements only and ignour the taken ones --- ///
        /// --- and that make for loop that try all subsets faster alot --- ///
            vi b;
            int size = 0;
            int tmp = Mask;
            while( tmp )
            {
                int lsone = LSOne(tmp);
                b.push_back(lsone);
                tmp -= lsone;
                size += 1;
            }

    /// --- Try All SubSets In The New Valid Smaller Set --- ///
        re = -OO;
        for(int pick = 0 ; pick < (1 << size) ; pick += 1)
        {
            int tmpMask = pick;  // Mask For Cur Taken SubSet Of Elements
            int newMask = Mask;  // Get New BitMask For The Next Elements

            // get num of distinct primes factors from it
            int sum = 0;

            // Iterate Over Taken Element And Update newMask and Sum --- ///
            while( tmpMask )
            {
                int lsone = LSOne(tmpMask);
                tmpMask -= lsone;

                int j = __builtin_ctz(lsone);
                sum += a[ __builtin_ctz(b[j]) ];

                // Turn Of bits that was valid and now taken
                newMask ^= b[j];
            }

            // Update DP
            re = max(re ,calc(i + 1 ,newMask) + numDiffPF[sum]);
        }

    return re;
}

int main()
{
    modified_sieve(15000);

    scanf("%d" ,&n);
    for(int i = 0 ; i < n ; i++)
        scanf("%d" ,&a[i]);

    memset(memo ,-1 ,sizeof memo);
    printf("%d" ,calc(0 ,(1 << n) - 1));
}