#include <iostream.h>
#include <fstream.h>          // for ifstream
#include <stdlib.h>           // for exit()
#include <ctype.h>            // for tolower()
#include <limits.h>           // for CHAR_MAX
#include "apstring.h"
#include "prompt.h"
#include "apvector.h"

// count # occurrences of all characters in a file
// written: 8/5/94
// by:      Owen Astrachan

void Print(const apvector<int> & counts, int total);
void Count(istream & input, apvector<int> & counts, int & total);

int main()
{
    int totalAlph = 0;    
    apstring filename = PromptString("enter name of input file: ");
    ifstream input(filename.c_str());

    if (input.fail() )
    {
        cout << "could not open file " << filename << endl;
        exit(1);
    }
    apvector<int> charCounts(CHAR_MAX,0); // all initialized to 0
    
    Count(input,charCounts,totalAlph);
    Print(charCounts,totalAlph);
    
    return 0;
}

void Count(istream & input, apvector<int> & counts, int & total)
// precondition: input open for reading
//               counts[k] == 0, 0 <= k < CHAR_MAX
// postcondition: counts[k] = # occurrences of character k
//                total = # alphabetic characters     
{
    apstring word;
    char ch;
    int k,len;
    while (input >> word)                   // read a word succeeded
    {
	len = word.length();                // # chars in word
	for(k=0; k < len; k++)
	{
	    ch = tolower(word[k]);          // convert to lower case
	    if (isalpha(ch))                // is alphabetic (a-z)?
	    {
		total++;
	    }
	    counts[ch]++;                   // count all characters   
	}
    }    
}

void Print(const apvector<int> & counts, int total)
// postcondition: all values of counts from 'a' to 'z' printed     
{
    cout.setf(ios::fixed);    // print 1 decimal place 
    cout.precision(1);
    
    char k;    
    for(k = 'a'; k <= 'z'; k++)
    {
        cout << k;
        cout.width(7);
        cout << counts[int(k)] << "  ";
        cout.width(4);
        //cout << 100 * double(counts[int(k)])/total << "%" << endl;
	cout << 100 * static_cast<double>(counts[k])/total << "%" << endl;
    }
}