c++ arrays and functions and counters - c++

Question

My code is done and working. But i cant figure out how to count the number of attempts made by the user and invalid account numbers that were entered. I am supposed to do this in main starting after cin >> accountNum. After the user enters 9999 to quit, it is supposed to display the number of attempts made and the number of invalid charge account numbers that were entered. When i run it i get 0 for number of attempts and -1 for invalid numbers entered.
#include <iomanip>
#include <iostream>
#include <fstream>
using namespace std;
void getAccountNumbers(int[], int);
void displayAccountNumbers(int[], int);
void selectionSort(int[], int);
int binarySearch(const int[], int, int);
int main()
{
int accountNum;
int results;
int attempts = 0;
int invalidNumbers = 0;
const int ARRAY_SIZE = 18; // Array size
int numbers[ARRAY_SIZE]; // Array with 18 elements
int count = 0;
//ifstream inputFile;
getAccountNumbers(numbers, ARRAY_SIZE);
cout << "Original Order" << endl;
displayAccountNumbers(numbers, ARRAY_SIZE);
selectionSort(numbers, ARRAY_SIZE);
cout << "Sorted List" << endl;
displayAccountNumbers(numbers, ARRAY_SIZE);
cout << "********************" << endl;
cout << "Enter an Account number or 9999 to quit" << endl;
cin >> accountNum;
if(accountNum == 9999)
{
cout << "Thank You!" << endl;
}
while(accountNum != 9999)
{
results = binarySearch(numbers, ARRAY_SIZE, accountNum);
if(results == -1)
{
cout << "That number was not found" << endl;
invalidNumbers = results++;
}
else
{
cout << "That number is valid " << endl;
}
attempts = results++;
cin >> accountNum;
}
cout << "Number of attempts: " << attempts << endl;
cout << "Invalid numbers entered: " << invalidNumbers << endl;
system("pause");
return 0;
}
void getAccountNumbers(int nums[], int size)
{
ifstream inputFile;
int count = 0;
//Open the file
inputFile.open("charges.txt");
while(count < size && inputFile >> nums[count])
count ++;
//Close the file
inputFile.close();
}
void displayAccountNumbers(int nums[], int size)
{
for(int count = 0; count < size; count++)
cout << nums[count] << "\t";
cout << endl << endl;
}
void selectionSort(int nums[], int size)
{
int startScan, minIndex, minValue;
for(startScan = 0; startScan < (size - 1); startScan++)
{
minIndex = startScan;
minValue = nums[startScan];
for(int index = startScan + 1; index < size; index++)
{
if(nums[index] < minValue)
{
minValue = nums[index];
minIndex = index;
}
}
nums[minIndex] = nums[startScan];
nums[startScan] = minValue;
}
}
int binarySearch(const int nums[], int size, int value)
{
int first = 0, //First element
last = size - 1, // Last element
middle, // Midpoint
position = -1; //Position of search value
bool found = false;
while(!found && first <= last)
{
middle = (first + last) / 2; //Midpoint
if(nums[middle] == value)
{
found = true;
position = middle;
}
else if(nums[middle] > value) // Value is in lower half
last = middle - 1;
else
first = middle + 1; // Value is in upper half
}
return position;
}

Answer 1

Your problem is in the lines where you are trying to add to invalidNumbers and attempts. The ++ postfix operator adds one to the number before it. You needn't say invalidNumbers = results++;; you merely need invalidNumbers++;, and the same applies for attempts. What your code was doing was setting invalidNumbers (and attempts) to the value of results and then adding one to results instead.