c_ch01_ex13.c

/*
 * Exercise 1-13.
 * Write a program to print a histogram of the lengths of words in its input.
 * It is easy to draw the histogram with the bars horizontal; a vertical
 * orientation is more challenging.
 */

#include <stdio.h>
#define	IN   1  /* inside a word */
#define	OUT  0  /* outside a word */
#define	MAXLEN 64
#define	HWIDTH 80

/* count lines, words, and characters in input */

main() {
	int c, state, i;
	int wlen[MAXLEN], len, max;


	state = OUT;
	len = 0;
	for (i = 0; i < MAXLEN; i++)
		wlen[i] = 0;
	max = 0;

	while ((c = getchar()) != EOF) {
		if (c == ' ' || c == '\n' || c == '\t') {
			if (state == IN) {
				state = OUT;
				/* we need to consider this word */
				if (len < MAXLEN) {
					++wlen[len];
				}
				len = 0;
			}
		} else {
			state = IN;
			++len;
		}
	}

	for (i = 0; i < MAXLEN; i++)
		if (wlen[i] > max)
			max = wlen[i];

	for (i = 0; i < MAXLEN; i++) {
		if (wlen[i]) {
			printf("%2d ", i);
			for (len = 0; len < (wlen[i]*HWIDTH)/max; len++)
				putchar('@');
			for (len = 0;
				len < HWIDTH - (wlen[i]*HWIDTH)/max; len++)
				putchar(' ');
			printf(" %6d\n", wlen[i]);
		}
	}

}