program not working as expected!

Question

Can anyone just help spot why my program is not returning the expected output. This is related to my previous question. I am passing a vector by reference; I want to see whats in the container before I copy them to another location. If you remove comments on loadRange, youu will see bids are generated by the trader.

#include <iostream> 
#include <vector> 
#include <string> 
#include <algorithm> 
#include <cstdlib>
#include <iomanip>   

using namespace std; 

const int NUMSELLER = 1; 
const int NUMBUYER = 1; 
const int NUMBIDS = 20; 
const int MINQUANTITY = 1; 
const int MAXQUANTITY = 30; 
const int MINPRICE =100; 
const int MAXPRICE = 150; 
int s=0;
int trdId;

// Bid, simple container for values 
struct Bid {  
        int bidId, trdId, qty, price;   
        char type; 

        // for sort and find.   
        bool operator<(const Bid &other) const { return price < other.price; }  
        bool operator==(int bidId) const { return this->bidId == bidId; }  
};  

// alias to the list, make type consistent 
typedef vector<Bid> BidList;

// this class generates bids! 
class Trader {  
private:  
        int nextBidId; 

public:  
        Trader(); 
        Bid getNextBid(); 
        Bid getNextBid(char type); 
        // generate a number of bids 
        void loadRange(BidList &, int size); 
        void loadRange(BidList &, char type, int size);
        void setVector();
};  

Trader::Trader() : nextBidId(1) {} 

#define RAND_RANGE(min, max) ((rand() % (max-min+1)) + min) 

Bid Trader::getNextBid() { 
        char type = RAND_RANGE('A','B');  
        return getNextBid(type); 
} 

Bid Trader::getNextBid(char type) {
        for(int i = 0; i < NUMSELLER+NUMBUYER; i++)
     {                 
       // int trdId = RAND_RANGE(1,9); 
        if (s<10){trdId=0;type='A';}
        else {trdId=1;type='B';}
        s++;
        int qty = RAND_RANGE(MINQUANTITY, MAXQUANTITY);  
        int price = RAND_RANGE(MINPRICE, MAXPRICE); 
        Bid bid = {nextBidId++, trdId, qty, price, type}; 
        return bid; 
} 
}
//void Trader::loadRange(BidList &list, int size) { 
//        for (int i=0; i<size; i++) { list.push_back(getNextBid()); } 
//} 
// 
//void Trader::loadRange(BidList &list, char type, int size) { 
//        for (int i=0; i<size; i++) { list.push_back(getNextBid(type)); } 
//}

//---------------------------AUCTIONEER-------------------------------------------

class Auctioneer {

vector<Auctioneer> List;
Trader trader;
vector<Bid> list;
public:
     Auctioneer(){};
    void accept_bids(const BidList& bid); 
};

    typedef vector<Auctioneer*> bidlist;

    void Auctioneer::accept_bids(const BidList& bid){    
    BidList list;
    //copy (BidList.begin(),BidList.end(),list);    
}

//all the happy display commands 
     void show(const Bid &bid) {  
     cout << "\tBid\t(" <<  setw(3) << bid.bidId << "\t " << setw(3) << bid.trdId
     << "\t " 
     << setw(3) <<  bid.type <<"\t " << setw(3) << bid.qty <<"\t "  << setw(3) << 
     bid.price <<")\t\n "  ;    
}  

void show(const BidList &list) {  
        cout << "\t\tBidID | TradID | Type  | Qty  |  Price  \n\n";   
        for(BidList::const_iterator itr=list.begin(); itr != list.end(); ++itr) {  
                //cout <<"\t\t";  
                show(*itr); 
                cout << endl;  
        }  
        cout << endl;  
} 

//search now checks for failure 
        void show(const char *msg, const BidList &list) {  
        cout << msg << endl; 
        show(list); 
} 

void searchTest(BidList &list, int bidId) {  
        cout << "Searching for Bid " << bidId << endl; 
        BidList::const_iterator itr = find(list.begin(), list.end(), bidId);  
        if (itr==list.end()) { 
                cout << "Bid not found.";  
        } else { 
                cout << "Bid has been found. Its : ";  
                show(*itr); 
        } 
        cout << endl;  
}  

//comparator function for price: returns true when x belongs before y 

        bool compareBidList(Bid one, Bid two) { 

        if (one.type == 'A' && two.type == 'B') 
                return (one.price < two.price); 

        return false; 
} 

void sort(BidList &bidlist) { sort(bidlist.begin(), bidlist.end(), compareBidList); }  


int main(int argc, char **argv) {  
         Trader trader; 
         BidList bidlist;  
         Auctioneer auctioneer;
         //bidlist list;
         auctioneer.accept_bids(bidlist);
         //trader.loadRange(bidlist, NUMBIDS); 
         show("Bids before sort:", bidlist);  
         sort(bidlist);  
         show("Bids after sort:", bidlist);  

        system("pause");
        return 0;  
}

Answer 1

If the problem is that the bids aren't sorted as expected, the problem is in the function compareBidList—it always returns false when the comparison isn't made so that the first bid is of type “A” and the second bid of type “B”. You should have it return the order you want in all cases. For one, you need to allow the comparison to be made in either order (first “B”, second “A”), otherwise it's inconsistent with itself.

(Even if this wasn't the problem you were asking about, it's still a problem. =)