Exercise 6-6. Implement a simple version of the #define processor (i.e., no arguments) suitable for use with C programs, based on the routines of this section. You may also find getch and ungetch useful. The processor reads C source line by line. When it sees #define NAME replacement it calls install from the hash table …
Exercise 6-4. Write a program that prints the distinct words in its input sorted into decreasing order of frequency of occurrence. Precede each word by its count. Count words using K&R’s binary tree (Section 6.5), then collect all nodes into an array and sort by count descending using qsort. The key insight: the tree is …
Exercise 6-3. Write a cross-referencer that prints a list of all words in a document, and for each word, a list of the line numbers on which it occurs. Remove noise words like “the”, “and”, and so on from the list. The data structure is a binary tree where each node holds the word and …
Exercise 6-1. Our version of getword does not properly handle underscores, string constants, comments, or preprocessor control lines. Write a better version. K&R’s getword from Section 6.3 reads the next identifier or non-alphabetic character from input, but has four gaps: Underscores: valid in C identifiers (_var, size_t) but the original checks only isalpha String constants: …