Sorting Arrays/File I/O C++ - c++

Question

I was wondering is someone could help me out of sorting this array, I am i little lost on how to exactly implement it in this project. Because it is HW do not reveal the whole answer, but push me towards the right direction. The project is as follows:
Write a program that will read a line of text and output a list of all the letters that occur in the text together with the number of times each letter occurs in the line. End the line with a period that serves as a sentinel value. The letters should be used in the following order: highest to lowest.Assume that the input used all lowercase letters.
A couple questions.
1. Am I going along the right way in sorting the array?
2. Before putting the sorting array into my code, when the code compiles it comes up with a blank screen. Any ways to fix this?
Apologies if this is written poorly, and thanks in advance for the help!
inlcude <iostream>
#inlcude <fstream>
using namespace std;
void initialize(int list[]);
void Sort(int list[],int& num);
void characterCount(char ch, int list[]);
void readText(ifstream& intext, char& ch, int list[]);
void totalCount(int list[]);
int main()
{
int index,letterCount[26];
char ch;
ifstream inFile;
infile.open("C:/temp/Data_Chapter_7_8.txt");
if (!inFile)
{
cout << " Cannot open file." <<endl;
}
initialize(letterCount);
infile.get(ch);
while (inFile)
{
int index;
readText(inFile,ch,letterCount)
index++;
inFile.get(ch);
}
totalCount(index, letterCount);
inFile.close();
system("PAUSE");
return 0;
}
//initializes array letterCount to 0
void initialize(int list[])
{
for(int x = 0;x<26;x++)
list[x] = 0
}
//increments the letter count. Makes sure counting letters.
void characterCount (char ch, int list[])
{
int index;
ch = tolower(ch);
if(static_cast<int>(ch)>=97&&(static_cast<int>(ch)<=122))
letterCount[static_cast<int>(ch)-97]++;
}
void readText(ifstream& intext, char& ch, int list[])
{
while (ch != '.')
{
characterCount (ch,list);
intext.get(ch);
}
}
//displays data
void totalCount(int list[])
{
for(int x=0;x<26;x++)
if(letterCount[x]>0)
cout<<static_cast<char>(x+97)<<" "<<letterCount[x]<<endl;
}
void Sort(int list[],int& num)
{
int i,j,flag = 1;
int temp;
int numLength = num.length();
for (i=1;(i<=numLength)&&flag; i++)
{
flag = 0;
for (j=o; j<(numLength-1);j++0
{
if(num[j+1]>num[j])
{
temp = num[j];
num[j] = num[j+1];
num[j+1]=temp;
flag = 1;
}
}
}
return;
}

Answer 1

Instead of using messy bubble sorts and other fun stuff, we can simply keep track of the number of occurrences of each letter, since there are only 26 possibilities. This should result in a bit cleaner (and much faster) code:
int numOccur[26];
...
for (int i = 0; i < numCh; i ++)
numOccur[letters[i] - 'a'] ++;
for (i = 25; i >= 0; i --)
if (i > 0)
cout<<static_cast<char>(i+97)<<" "<<numOccur[i]<<endl;
Of course, you should replace the for loop with the appropriate file-reading loop.

Answer 2

Just a few comments.
I don't see any good reason for most of the casting here.
Use isalpha, isupper or islower to check for letters, and tolower or toupper to covnert them (Note: using these functions is one of the few justifications for casting).
Probably easiest to initialize your lettercount array with `int lettercount[26] ={0};
Unless you're absolutely required to write your own sort routine, just use std::sort.
It's usually easiest to open a file as you define your ifstream:
std::ifstream infile("whatever");
Don't use while (infile). It's pretty much a guaranteed bug. Do a read, and check whether it succeeded, like: while (infile.get(ch)) ...