Exercise 1-14

Exercise 1-14  Write a program to print a histogram of the frequencies of different characters in its input.

#include <ctype.h>

#include <limits.h>

#include <stdio.h>

#define MAX_WIDTH 65

#define RANGE CHAR_MAX-CHAR_MIN+1

int main(void)

{

  int c;

  unsigned int i;

  unsigned int count[RANGE];

  for (i = 0; i < RANGE; i++)

    count[i] = 0;

  while (c=getchar(), c!=EOF)

  {

    if (count[c-CHAR_MIN]<MAX_WIDTH)

      count[c-CHAR_MIN]++;

  }

  for (i = 0; i < RANGE; i++)

  {

    if (count[i])

    {

      if (isprint(i+CHAR_MIN))

        printf ("%4d '%c' : ", i+CHAR_MIN, i+CHAR_MIN);

      else

        printf ("%4d     : ", i+CHAR_MIN);

      do

      {

        putchar('*');

        count[i]--;

      }

      while(count[i]);

      putchar('\n');

    }

  }

  return 0;

}