Question

I have been looking at this piece of code for the last 3 hours and I am pretty stuck. I appreciate any help, thank you.

file: UnsortedType.h

#include "ItemType.h"
class UnsortedType{

public:
    UnsortedType();
    void RetireveItem(ItemType& item, bool& found);
    bool InsertItem(ItemType item);
private:
    int length;
    ItemType info[MAX_ITEMS];
};

file: UnsortedType.cpp

#include "UnsortedType.h"
#include <iostream>

UnsortedType::UnsortedType() {
    length = 0;
}

void UnsortedType::RetireveItem(ItemType& item, bool& found) {

    bool moreToSearch = true;
    int location = 0;
    found = false;

    moreToSearch = (location < length);

    while (moreToSearch && !found) {

        switch (item.ComparedTo(info[location])) {
            case LESS:
                location++;
                moreToSearch = (location < length);
                break;
            case GREATER:
                location++;
                moreToSearch = (location < length);
                break;
            case EQUAL:
                found = true;
                break;
        }
    }

    if (found) {
        item = info[location];
        std::cout << "Item " << item.getValue() << " has been retrieved." << std::endl;
    }

    else {
        std::cout << "Item " << item.getValue() << " has NOT found and has NOT been retrieved."
    }
}

bool UnsortedType::InsertItem(ItemType item) {

    if (length == MAX_ITEMS) {
        std::cout << "List is Full!" << std::endl;
        std::cout << "Item " << item.getValue() << " has not been added." << std::endl;
        return false;
    } else {
        std::cout << "Item " << item.getValue() << " added successfully." << std::endl;
        info[length] = item;
        length++;
        return true;
    }
}

file: ItemType.h

const int MAX_ITEMS = 40;
enum RelationType{LESS,GREATER,EQUAL};

class ItemType{

private:
    int value;

public:
    ItemType();
    ItemType(int value);
    RelationType ComparedTo(ItemType otherItem);
    void Initialize(int value);
    void printItem();
    int getValue();
};

file: ItemType.cpp

ItemType::ItemType(){
    this->value=0;    
}

ItemType::ItemType(int value){
    this->value = value;
}

RelationType ItemType::ComparedTo(ItemType otherItem){

    if(value < otherItem.value){
        return LESS;
    }

    if(value == otherItem.value){
        return EQUAL;
    }

    if(value < otherItem.value){
        return GREATER;
    }    

}

void ItemType::Initialize(int value){
    this->value = value;
}

void ItemType::printItem(){
    std::cout << "Item Type: " << this->value <<std::endl;
}

int ItemType::getValue(){
    return this->value;
}

Please note: In the above code, I have ommited some code parts that I think that are not relevant. Therefore if you copy / paste the code and run it may require some include statements ( like iostream ) and so..

Now here is the question:

When I run the main like this:

UnsortedType unsortedType;

bool item3found = false;
ItemType item3(3);
unsortedType.InsertItem(item3);
unsortedType.RetireveItem(item3, item3found);

bool item1found = false;
ItemType item1(1);
unsortedType.InsertItem(item1);
unsortedType.RetireveItem(item1, item1found);

bool item2found = false;
ItemType item2(2);
unsortedType.RetireveItem(item2, item2found);

There are no problems.

The output is:

Item 3 added successfully.
Item 3 has been retrieved.
Item 1 added successfully.
Item 1 has been retrieved.
Item 2 has NOT found and has NOT been retrieved.

However if I first add item1 and retrieve item1, then add item3 and retrieve item3, the switch statement suddenly stops working.

So this is the main file in the weird situation:

UnsortedType unsortedType;

bool item1found = false;
ItemType item1(1);
unsortedType.InsertItem(item1);
unsortedType.RetireveItem(item1, item1found);

bool item3found = false;
ItemType item3(3);
unsortedType.InsertItem(item3);
unsortedType.RetireveItem(item3, item3found);

bool item2found = false;
ItemType item2(2);
unsortedType.RetireveItem(item2, item2found);

While debugging the program I keep myself finding in:
while (moreToSearch && !found)
and the code does not go to ANY of the switch statements. Any idea?

This is the output in the weird situation:

Item 1 added successfully.
Item 1 has been retrieved.
Item 3 added successfully.

RUN FAILED (exit value 1, total time: 1s)

Any help greatly appropriated, I am about to lose it!

Answer 1

The problem looks to be in your ComparedTo member function:

RelationType ItemType::ComparedTo(ItemType otherItem){

    if(value < otherItem.value){
        return LESS;
    }

    if(value == otherItem.value){
        return EQUAL;
    }

    if(value < otherItem.value){
        return GREATER;
    }    

}

The comparison for the GREATER case doesn’t appear to be correct. For such a function, it would make sense that you don’t allow a possible path through it that won’t return a value (i.e., use if, else if, else). Also, you might want to turn on all compiler warnings and treat them as errors; it would help to avoid a problem like this.