HackerRank

All about pruning and duplication removal. Took me several submissions to get it AC:

#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <unordered_map>
using namespace std;

#define BOUND (1000000007)
int main() 
{
    //    Get input
    int n, m; cin >> n >> m;
    vector<long long> A(n);
    for(int i = 0; i < n; i ++)        cin >> A[i];
    vector<long long> B(m);
    for(int i = 0; i < m; i ++)        cin >> B[i];
    vector<long long> C(m);
    for(int i = 0; i < m; i ++)        cin >> C[i];

    //
    unordered_map<int, long long> hm;
    for(int i = 0; i < m; i ++)
    {
        if(hm.find(B[i]) == hm.end())
        {
            hm[B[i]] = C[i];
        }
        else
        {
            hm[B[i]] *= C[i];
            hm[B[i]] %= BOUND;
        }
    }

    //
    long long facOne = 1;
    for(auto &e: hm)
    {
        if(e.first == 1)
        {
            facOne *= e.second;
            facOne %= BOUND;
            continue;
        }

        int j = e.first - 1;
        while(j < n)
        {
            A[j] *= e.second;
            A[j] %= BOUND;
            j += e.first;
        }
    }

    //
    for_each(A.begin(), A.end(), [&](long long v){
        v = (v * facOne) % BOUND;
        cout << v << " ";});
    return 0;
}