Letter Distribution Calculator

letter_count.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "letter_count.h"

int main (int argc, char const* argv[])
{
	int i;
	for (i=1;i<argc; i++){
		letter_distribution_of(argv[i]);
	}
	return 0;
}

void letter_distribution_of(const char *value){
	int i;
	int *letter_counts = (int *) malloc(2 * sizeof(int));
	int current_length=2;
	for(i=0;i<strlen(value);i++){
		int j;
		int changed = 0;
		for (j=0;j<current_length-2;j+=2){
			if(value[i] == letter_counts[j]){
				letter_counts[j+1]++;
				changed = 1;
			}
		}
		if(changed == 0){
			letter_counts[current_length-2] = value[i];
			letter_counts[current_length-1] = 1;
			if(i < strlen(value)-2)
			current_length += 2;
			letter_counts = (int *) realloc(letter_counts, current_length * sizeof(int));
		}
	}
	printf("Letter Distribution of %s:\n", value);
	for(i=0;i<current_length;i+=2){
		printf("%c:%d\t",letter_counts[i], letter_counts[i+1]);
	}
	free(letter_counts);
	puts(""); //newline for formatting.
}

letter_count.h

#ifndef LETTER_COUNT_H
#define LETTER_COUNT_H 

/* function declarations */
void letter_distribution_of(const char *value);

#endif