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Answer to Exercise 4-4, page 79 Solution by Bob Wightman Add commands to print the top element of the stack without popping, to duplicate it, and to swap the top two elements. Add a command to clear the stack. #include #include #include #include #define MAXOP 100 #define NUMBER 0 #define TRUE 1 #define FALSE 0 /* This programme is a basic calculator. Extra cases have been added to: 1. Show the t..

Answer to Exercise 4-3, page 79 Solution by Bob Wightman Given the basic framework, it's straightforward to extend the calculator. Add the modulus ( % ) operator and provisions for negative numbers. In Bob's words: "Here's my attempt Adding the modulus is easily done by another case in main and using the fmod function. The standard library has been mentioned at this point so it should be valid t..

Answer to Exercise 4-2, page 73 Solution by Dann Corbit Extend atof to handle scientific notation of the form 123.45e-6 where a floating-point number may be followed by e or E and an optionally signed exponent. /* ** Written by Dann Corbit as K&R 2, Exercise 4-2 (Page 73). ** Keep in mind that this is *JUST* a student exercise, and is ** light years away from being robust. ** ** Actually, it's k..

Answer to Exercise 4-1, page 71 Solution by Rick Dearman Write the function strrindex(s,t) , which returns the position of the rightmost occurrence of t in s , or -1 if there is none. /* Test driver by Richard Heathfield * Solution (strrindex function) by Rick Dearman */ #include /* Write the function strrindex(s,t), which returns the position ** of the rightmost occurrence of t in s, or -1 if t..

Answer to Exercise 3-6, page 64 Solution by Paul Griffiths Write a version of itoa that accepts three arguments instead of two. The third argument is a minimum field width; the converted number must be padded with blanks on the left if necessary to make it wide enough. /* EX3_6.C ======= Suggested solution to Exercise 3-6 */ #include #include void itoa(int n, char s[], int width); void reverse(c..

Answer to Exercise 3-5, page 64 Solution by Paul Griffiths Write the function itob(n,s,b) that converts the integer n into a base b character representation in the string s . In particular, itob(n,s,16) formats n as a hexadecimal integer in s . /* EX3_5.C ======= Suggested solution to Exercise 3-5 */ #include #include void itob(int n, char s[], int b); void reverse(char s[]); int main(void) { ch..

Answer to Exercise 3-4, page 64 Solution by Paul Griffiths - error spotted by Wayne Lubin and fixed. Wayne Lubin's query involved Paul's discussion of two's complement. The text has now been corrected (by Paul). In a two's complement number representation, our version of itoa does not handle the largest negative number, that is, the value of n equal to -(2 to the power (wordsize - 1)) . Explain ..

Answer to Exercise 3-3, page 63 Solution by Paul Griffiths Write a function expand(s1,s2) that expands shorthand notations like a-z in the string s1 into the equivalent complete list abc...xyz in s2 . Allow for letters of either case and digits, and be prepared to handle cases like a-b-c and a-z0-9 and -a-z . Arrange that a leading or trailing - is taken literally. /* EX3_3.C ======= Suggested s..

Answer to Exercise 3-2, page 60 Solution by Paul Griffiths Write a function escape(s,t) that converts characters like newline and tab into visible escape sequences like \n and \t as it copies the string t to s . Use a switch . Write a function for the other direction as well, converting escape sequences into the real characters. /* EX3_2.C ======= Suggested solution to Exercise 3-2 */ #include v..

Answer to Exercise 3-1, page 58 Solutions by Paul Griffiths Colin Barker and Andrew Tesker Our binary search makes two tests inside the loop, when one would suffice (at the price of more tests outside). Write a version with only one test inside the loop and measure the difference in run-time. Paul Griffiths' solution (krx30100.c): /* Solution by Paul Griffiths (paul@paulgriffiths.demon.co.uk) */..