For-loop with strings not working - c++

Question

Here is the instructions:
Write a program that reads in a text file one word at a time. Store a word into a dynamically created array when it is first encountered. Create a paralle integer array to hold a count of the number of times that each particular word appears in the text file. If the word appears in the text file multiple times, do not add it into your dynamic array, but make sure to increment the corresponding word frequency counter in the parallel integer array. Remove any trailing punctuation from all words before doing any comparisons.
Create and use the following text file containing a quote from Bill Cosby to test your program.
I don't know the key to success, but the key to failure is trying to please everybody.
At the end of your program, generate a report that prints the contents of your two arrays
Here is my Code:
#include <iostream>
#include <fstream>
#include <string>
#include <cstring>
#include <cctype>
using namespace std;
int main()
{
ifstream inputFile;
int numWords;
string filename;
string *readInArray = 0;
char testArray[300] = {0};
char *realArray = 0;
const char *s1 = 0;
string word;
int j =1;
int k = 0;
int start =0;
int ending = 0;
char wordHolder[20] = {0};
cout << "Enter the number of words the file contains: ";
cin >> numWords;
readInArray = new string[(2*numWords)-1];
cout << "Enter the filename you wish to read in: ";
cin >> filename;
inputFile.open(filename.c_str());
if (inputFile)
{
cout << "\nHere is the text from the file:\n\n";
for (int i=0; i <= ((2*numWords) -1); i +=2)
{
inputFile >> readInArray[i]; // Store word from file to string array
cout << readInArray[i];
strcat(testArray, readInArray[i].c_str()); // Copy c-string conversion of word
// just read in to c-string
readInArray[j] = " ";
cout << readInArray[j];
strcat(testArray, readInArray[j].c_str()); // This part is for adding spaces in arrays
++j;
}
inputFile.close();
}
else
{
cout << "Could not open file, ending program";
return 0;
}
realArray = new char[strlen(testArray)];
cout << "\n\n";
for(int i=0; i < strlen(testArray); ++i)
{
if (isalpha(testArray[i]) || isspace(testArray[i])) // Is makes another char array equal to
{ // the first one but without any
realArray[k]=testArray[i]; // Punctuation
cout << realArray[k] ;
k++;
}
}
cout << "\n\n";
for (int i=0; i < ((2*numWords) -1); i+=2)
{
while (isalpha(realArray[ending])) // Finds space in char array to stop
{
++ending;
}
cout << "ending: " << ending << " ";
for ( ; start < ending; ++start) // saves the array up to stopping point
{ // into a holder c-string
wordHolder[start] = realArray[start];
}
cout << "start: " << start << " ";
readInArray[i] = string(wordHolder); // Converts holder c-string to string and
cout << readInArray[i] << endl; // assigns to element in original string array
start = ending; // Starts reading where left off
++ending; // Increments ending counter
}
return 0;
}
Output:
Enter the number of words the file contains: 17
Enter the filename you wish to read in: D:/Documents/input.txt
Here is the text from the file:
I don't know the key to sucess, but the key to failure is trying to please everybody.
I dont know the key to sucess but the key to failure is trying to please everybody
ending: 1 start: 1 I
ending: 6 start: 6 I dont
ending: 11 start: 11 I dont know
ending: 15 start: 15 I dont know the
ending: 19 start: 19 I dont know the key
ending: 22 start: 22 I dont know the key to>
ending: 29 start: 29 I dont know the key to sucess
ending: 33 start: 33 I dont know the key to sucess but↕>
My Question:
Something is wrong with the last for-loop, it crashes after I run it. I included the ending and starting variables to maybe help see whats going on. I know there are better ways of doing this problem but the instructor wants it done this way. If you know where I went wrong with the last for-loop any help would be very much appreciated!!

Answer 1

You aren't null-terminating your strings as you go along. You copy the characters correctly, but without null terminators, your loops might go off into the weeds.