#include<iostream>
#include<fstream>
#include<cstring>
using namespace std;
struct letter
{
	int upper;
	int lower;
};
void openFiles(ifstream &, ofstream &);
void countLetters(letter[], ifstream &);
void setZero(letter[]);
void printLetters(letter[],ofstream &);
int main()
{
	letter countAlpha[26];
	ifstream inFile;
	ofstream outFile;
	

	//call a function to open our files

	 openFiles(inFile, outFile);

	//call a function to count all the letters in the file

	 countLetters(countAlpha, inFile);

	//call a function to print results

	 printLetters(countAlpha, outFile);

	return 0;
}
void openFiles(ifstream & in, ofstream & out)
{
	//funtion to open input and output files
	//when returns to main both files are open
	char inputFileName[20];
	char outputFileName[20];
	cout << "Enter the name of your input file";
	cin >> inputFileName;
	cout << "Enter the name of your output file";
	cin >> outputFileName;

	in.open(inputFileName);
	if (!in)
	{
		cout << "Error opening file " << inputFileName << endl;
		exit(1);
	}

	out.open(outputFileName);
	if (!out)
	{
		cout << "Error opening file " << outputFileName << endl;
		exit(1);
	}
	//if declared:  string inputFileNameString;
	//in.open (inputFileNameString.c_str());
}
void setZeros(letter B[])
{
	int i;
	for (i = 0; i < 26; i++)
	{
		B[i].lower = 0;
		B[i].upper = 0;
	}
}

void countLetters(letter letA[], ifstream & in)
{
	char ch;
	
	setZeros(letA);
	in.get(ch);
	while (!in.eof())
	{
		
		if (ch >= 'a' && ch <= 'z')
			letA[ch - 97].lower++;
		else if (ch >= 'A' && ch <= 'Z')
			letA[ch - 65].upper++;

		in.get(ch);
	}
}

void printLetters(letter letA[], ofstream & out )
{
	int i;
	for (i = 0; i < 26; i++)
	{
		cout << static_cast<char>(i + 65) << ' ' <<
			letA[i].upper << "     " <<static_cast<char>(i + 97)
			<< ' ' << letA[i].lower << endl;
	}
}