Exercise 4-8. Suppose that there will never be more than one character of pushback. Modify getch and ungetch accordingly. The original K&R implementation uses an array buf[BUFSIZE] and an index bufp to support multiple pushed-back characters. If only one character of pushback is ever needed, the array becomes unnecessary. A single static int buf suffices …
Exercise 4-7. Write a routine ungets(s) that will push back an entire string onto the input. Should ungets know about buf and bufp, or should it just use ungetch? The answer is: ungets should use ungetch, not access buf and bufp directly. This is the principle of information hiding — getch and ungetch own the …
Exercise 4-6. Add commands for handling variables. (It’s easy to provide for twenty-six variables with single-letter names.) Add a variable for the most recently printed value. Twenty-six variables map naturally to an array var[26] indexed by c – ‘a’. The protocol: a lowercase letter pushes its variable’s value; = assigns the top of the stack …
Exercise 4-5. Add access to library functions like sin, cos, exp, and pow. See <math.h> in Appendix B, Section 4. Math functions need the calculator to recognize words as well as single characters. getop currently returns one character at a time. The fix: if getop sees a letter, it reads the whole word into s[] …
Write C Program to add one to digits of a number. C Program that adds the 1 to each single digit of a number, i.e for Example 12345’s output is 23456. If the digit is 9 it adds 1 and follows the carry system, 9 becomes 0 and 9’s left digit adds one more 1. …
Data structures using C,Write a C Program to implement Priority Queue using structure.Priority QUEUE is a abstract data type in which the objects are inserted with respect to certain priority. In this program, we created the simple ascending order priority queue using the structure, here items are inserted in ascending order. Structure is a c …