C++ Array Processing - c++

Question

I am having trouble debugging this code so it reads two columns from the file and when the first column (Department is the same it just adds the second column to the old dept already created)This code is having trouble with looping. Any walk through, help would be much appreciated ! Thanks.
#include <iostream>
#include <fstream>
using namespace std;
ifstream inputFile; //stream object
int main()
{
inputFile.open("text.txt");
const int SIZE = 15;
int candy[SIZE];
int dept[SIZE];
int valuecounter = 0;
int Candy;
int Department;
while (inputFile >> Department >> Candy)
{
// Exit loop if we have filled the entire array
if (valuecounter == SIZE)
break;
// Update previous values
for (int index = 0; index < valuecounter; index++)
{
if (dept[index] == Department)
{
candy[index] += Candy;
}
}
// Update current values and increment counter
dept[valuecounter] = Department;
candy[valuecounter] = Candy;
valuecounter++;
}
for (int i = 0; i < valuecounter ; i++)
cout << dept[i] << " " << candy[i] << endl;
inputFile.close();
return 0;
}
and the list of input being for ex:
910 8
450 9
750 10
150 35
750 19
150 18
910 19
390 19
520 6
110 78
300 23
110 1
110 5
120 6
150 16
300 23
110 1
110 5
120 6
150 16
the array should be partially filled. but it produces weird outcome! logic error?

Answer 1

You have initialized valuecounter, and all elements of array dept, to zero. For this reason, in every iteration of the while loop, condition dept[valuecounter] == NULL will always evaluate to true. This means that, in every iteration, only code in the first if statement will execute.
Note that this is not the only problem with this code. As user Crazy Eddie pointed out, using NULL as an integer is considered very bad practice.
EDIT:
Replace your while loop with the following:
while (inputFile >> Department >> Candy)
{
// If this Department already exists ...
for (int index = 0; index < valuecounter; index++)
{
if (dept[index] == Department)
{
// ... update the corresponding value in 'candy' and continue the loop
candy[index] += Candy;
continue;
}
}
// If this Department does not exist, and if there are are more
// available array elements, assign a new Department
if (valuecounter < SIZE)
{
dept[valuecounter] = Department;
candy[valuecounter] = Candy;
valuecounter++;
}
}

Answer 2

int main()
{
const int SIZE = 15;
int candy[SIZE];
int dept[SIZE];
int valuecounter = 0;
int Candy;
int Department;
inputFile.open("text.txt");
if (!inputFile)
{
cout << "\nError opening file" << endl
<< "Exiting\n" << endl;
exit(1);
}
while (valuecounter < SIZE && inputFile >> Department >> Candy)
{
//setting bool to false everytime loop starts over.
bool found = false;
for (int index = 0; index < valuecounter; index++)
{
if (dept[index] == Department)
{
candy[index] += Candy;
//setting bool to true if department found
found = true;
}
}
if (!found)
{
dept[valuecounter] = Department;
candy[valuecounter] = Candy;
valuecounter++;
}
}
inputFile.close();
if (valuecounter == 0)
{
cout << "\n\nEMPTY FILE\nExiting.\n\n" << endl;
exit(1);
}
here i had three different functions do different things with data
return 0;
}
basically what i was missing is to set bool back to false whenever while loop started over this is why data wasn't calculated properly. Anyways Thank you all for help and all the tips!