Exercise 1-12. Write a program that prints its input one word per line.

对应于自己练习的kr_10.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.

未做

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

in its input.