K&R, изд. 3, исп., или начал изучать Си.

#include <stdio.h>
#define MAXCOUNT 1000
#define OUTW 0
#define INW 1
#define DELIMITER "  "
/* Write a program that makes a word length histo */
int main() {
  int wordlen[MAXCOUNT];
  int c, i, j, wc, m, state;
  for (i = 0; i < MAXCOUNT; ++i) wordlen[i] = 0;
  c = i = j = wc = m = 0;
  state = OUTW;
  while ((c = getchar()) != EOF && wc < MAXCOUNT - 1 ) {
    if (c == ' ' || c == '\t' || c == '\n') {
      state = OUTW;
      ++wordlen[wc];
      ++wc;
    }
    else if (state == OUTW)
      state = INW;
    else ++wordlen[wc];
  }
  printf("Building histograms. First, horizontal:\n");
  for (i = 0; i < wc; ++i) {
    printf("word %d: ", i);
    for (j = 0; j < wordlen[i]; ++j) putchar('+');
    putchar('\n');
  }
  printf("Then, vertical:\n");
  /* what's the longest word? */
  m = 0;
  for (i = 0; i < wc; ++i)
    if (wordlen[i] > m) m = wordlen[i];
  for (i = 0; i < m; ++i) {
    for (j = 0; j < wc; ++j) {
      if (wordlen[j] >= m) putchar('+');
      else putchar(' ');
      printf(DELIMITER);
    }
    putchar('\n');
    --m;
  }
  /* the legend under histogram */
  for (i = 0; i < wc; ++i)
    printf("%d%s", i, DELIMITER);
  putchar('\n');
}

./1.13_words_histo 
this is another words
Building histograms. First, horizontal:
word 0: ++++
word 1: ++
word 2: +++++++
word 3: +++++
Then, vertical:
      +     
      +     
      +  +  
+     +  +  
0  1  2  3