#include "stdafx.h"
#include <iostream>
#include <fstream>
#include <cassert>
#include <vector>
#include <numeric>
#include <string>
using namespace std;

void read(ifstream & fin, vector<char> & letter, vector<double> & occ);
void results(ofstream & fout, vector<char> & letter, vector<double> & occ);

int _tmain(int argc, _TCHAR* argv[])
{
cout<<"To find the number of occurences of each letter " <<endl
<<"in a file, please enter the filename: ";
string infile;
cin>>infile;
cout<<"\nEnter the name of the output file: ";
string outfile;
cin>>outfile;

ifstream fin(infile.data()); 
ofstream fout(outfile.data());
assert(fin.is_open() && fout.is_open()); 

vector<char> letter;
vector<double> occ;

//code...
char c;
int i=0;
while(fin)
{
    fin>>c;
    if(c == 'a')       // 'a' is the character to  be searched from the file
        i++;
}  
cout<<"The number of occurences is "<<i;
//code...

    if(c == 'a') // change the 'a' here to any letter you want

int main() 
{
    // code..