Priyank

#include <iostream>
#include <hash_map>
#include <list>
#include <set>
#include <bitset>
#include <string>

using namespace std;
using namespace stdext;

const int PAGE_VIEW_COUNT = 3;
const int DAYS_VISIT_COUNT = 2;

class CustomerData
{
public:
  bitset<PAGE_VIEW_COUNT> days;
  set<int> pages;

  CustomerData(bitset<PAGE_VIEW_COUNT> d, set<int> p) : days(d), pages(p)
  {
  }

  CustomerData() : days(string("000")) //Use days.reset, if PAGE_VIEW_COUNT != 3
  {
  }
};

hash_map<int, CustomerData> entries;
hash_map<int, CustomerData>::const_iterator recordIter;
typedef pair<int, CustomerData> CustomerRecordEntry;

void GenerateCustomerList(const list<pair<int, int>>& cuslist, int logNum);

int main()
{
  list<pair<int, int>> log1, log2, log3;
  log1.push_back(make_pair(1,1));
  log1.push_back(make_pair(2,2));
  log1.push_back(make_pair(4,1));
  log1.push_back(make_pair(1,3));

  log2.push_back(make_pair(2,1));
  log2.push_back(make_pair(2,4));
  log2.push_back(make_pair(4,2));
  log2.push_back(make_pair(1,3));
  log2.push_back(make_pair(1,5));

  log3.push_back(make_pair(3,2));
  log3.push_back(make_pair(4,4));
  log3.push_back(make_pair(5,2));
  log3.push_back(make_pair(5,5));

  GenerateCustomerList(log1, 1);
  GenerateCustomerList(log2, 2);
  GenerateCustomerList(log3, 3);

  int cid = 0;
  cout << "Enter customer ID: " ;
  cin >> cid;

  recordIter = entries.find(cid);
  if(recordIter != entries.end())
  {
    CustomerData data = (CustomerData)recordIter->second;
    if(data.days.count() == DAYS_VISIT_COUNT && data.pages.size() == PAGE_VIEW_COUNT)
    {
      cout << "Customer visited on exactly 2 days and have 3 or more distinct page views."
        << endl;
    }
    else
    {
      cout <<
        "Customer didn't visited on exactly 2 days or have 3 or more distinct page views."
        << endl;
    }
  }
  else
    cerr << "Customer ID not found in logs." << endl;

  cout << endl;
  return 0;
}

void GenerateCustomerList(const list<pair<int, int>>& cuslist, int logNum)
{
  list<pair<int, int>>::const_iterator iter;
  for(iter = cuslist.begin(); iter != cuslist.end(); iter++)
  {
    recordIter = entries.find(iter->first);
    if(recordIter != entries.end())
    {
      CustomerData data = (CustomerData)recordIter->second;
      data.days.set((logNum-1), true);
      //Space optimization
      //Check if already have 3 distinct page view, no need to add more
      if(data.pages.size() < PAGE_VIEW_COUNT)
        data.pages.insert(iter->second);
      entries[recordIter->first] = data;
    }
    else
    {
      bitset<PAGE_VIEW_COUNT> days(string("000"));
      days.set((logNum-1), true);
      set<int> pages;
      pages.insert(iter->second);
      CustomerData data(days, pages);
      entries.insert(CustomerRecordEntry(iter->first, data));
    }
  }
}