counting occurrence of character and printing them out - c

Question

I've managed to get the frequency of the alphabet from my input. I also found the largest occurred character. But i dont know how to print the actual character. Right now my program displays A-Z and display the occurrence for each alphabet. I want to be able on the next line print out the largest occurred letter and how many times it occurred.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#define MAX 200
int readLine(char string[]);
void find_frequency(char string[], int count[]);
int maxArray(int a[]);
int main(void)
{
char array[MAX];
int freq[MAX];
int nrOfChar;
int i;
char c;
int max;
printf("Command Line Tool\n");
printf("Please enter text here: ");
nrOfChar = readLine(array);
for(c = 'A'; c<= 'Z'; c++)
{
printf("%c ", c);
}
find_frequency(array, freq);
printf("\n");
for(i=0;i<26;i++)
{
printf("%d ", freq[i]);
}
printf("\n");
max=maxArray(freq);
printf("Print letter and how many occurrence.\n");
printf("Finished excuting.\n");
return 0;
}
int readLine(char string[])
{
int ch;
int i=0;
while (isspace(ch = getchar()))
;
while (ch != '\n' && ch != EOF)
{
if (i < MAX)
{
string[i++] = ch;
ch = getchar();
}
}
string[i] = '\0';
return i;
}
void find_frequency(char string[], int count[])
{
int i;
for(i = 0; string[i] != '\0'; i++)
{
if (string[i] >= 'A' && string[i] <= 'Z' )
{
count[string[i]-'A']++;
}
}
}
int maxArray(int a[])
{
int i, max=0;
for (i=0; i<26; i++)
{
if (a[i]>max)
{
max=a[i];
}
}
return max;
}

Answer 1

Below I've incorporated various folks' suggestions from the comments as well as some other fixes and style changes for you to consider:
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#define ALPHABET_LENGTH 26
#define MAXIMUM_CHARACTERS 200
int readLine(char string[], int maximum);
void findFrequency(char string[], int count[]);
int findMaximumIndex(int array[], int length);
int main(void)
{
char characters[MAXIMUM_CHARACTERS];
int frequencies[ALPHABET_LENGTH];
printf("Command Line Tool\n");
printf("Please enter text here: ");
(void) readLine(characters, MAXIMUM_CHARACTERS);
for (char c = 'A'; c <= 'Z'; c++)
{
printf("%c ", c);
}
printf("\n");
findFrequency(characters, frequencies);
for (int i = 0; i < ALPHABET_LENGTH; i++)
{
printf("%d ", frequencies[i]);
}
printf("\n");
int maximum = findMaximumIndex(frequencies, ALPHABET_LENGTH);
printf("%c occurred most often (%d times)\n", maximum + 'A', frequencies[maximum]);
printf("Finished excuting.\n");
return 0;
}
int readLine(char string[], int maximum)
{
int c, count = 0;
while (isspace(c = getchar()))
;
while (c != EOF && c != '\n')
{
if (count < maximum - 1)
{
string[count++] = c;
c = getchar();
}
}
string[count] = '\0';
return count;
}
void findFrequency(char string[], int count[])
{
for (int i = 0; string[i] != '\0'; i++)
{
char c = string[i];
if (c >= 'A' && c <= 'Z' )
{
count[c - 'A']++;
}
}
}
int findMaximumIndex(int array[], int length)
{
int index = 0;
for (int i = 1; i < length; i++)
{
if (array[i] > array[index])
{
index = i;
}
}
return index;
}
EXAMPLE OUTPUT
> ./a.out
Command Line Tool
Please enter text here: IN TEACHING OTHERS WE TEACH OURSELVES
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
2 0 2 0 6 0 1 3 2 0 0 1 0 2 2 0 0 2 3 3 1 1 1 0 0 0
'E' occurred most often (6 times)
Finished excuting.
>
Things yet to ponder: your output won't look as nice if any character occurs more than 9 times -- how can you fix that; you might want to deal with mixed case as an option in your readLine() routine to uppercase the input; there may be a (multi-way) tie for the most frequently occuring letter, can you deal with that; your readLine() returns a count of characters that you don't do anything with -- how might it be useful (possibly in error checking)?