이진우의 블로그

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. Solution by Richard Heathfield Bug (noticed by John W Krahn) fixed 11 June 2002. The noise word list was broken because it contained out-of-order data. I fixed this, and made the program more generally useful, ..

Our version of getword does not properly handle underscores, string constants, comments, or preprocessor control lines. Write a better version. Solution by Ben Pfaff /* K&R 6-1: "Our version of getword() does not properly handle underscores, string constants, or preprocessor control lines. Write a better version." This is intended to be a solution to K&R 6-1 in "category 0" as defined by the off..

#include #include #include #include #define AUTHOR "Robert Taylor" #define CREATION_DATE "May, 2014" #define LAST_UPDATE __DATE__ /* last date that binary was compiled */ static char *program_name; /* My solution to Exercise 5-17 * of the C Programming Language (second edition) * by Brian W. Kernighan * and Denis M. Ritchie * * To compile: * gcc -Os -Wall -s -o sort sort.c * * For help: * ./sort..

Write the program tail, which prints the last n lines of its input. By default, n is 10, say, but it can be changed by an optional argument, so that tail -n prints the last n lines. The program should behave rationally no matter how unreasonable the input or the value of n. Write the program so it makes the best use of available storage; lines should be stored as in the sorting program of Sectio..

Extend entab and detab to accept the shorthand entab -m +n to mean tab stops every n columns, starting at column m. Choose convenient (for the user) default behavior. Solution by Franz Fritsche /* * entab.c (Exercise 5-12) * Author : Franz Fritsche * About : Replaces strings of blanks with the minimum number * of tabs and blanks to achieve the same spacing. * Usage : entab -m +n * (tab stops eve..

Modify the programs entab and detab (written as exercises in Chapter 1) to accept a list of tab stops as arguments. Use the default tab settings if there are no arguments. Solution by Gregory Pietsch Here's detab... /**************************************************************************** detab.c - Source code for the detab command AUTHOR: Gregory Pietsch DESCRIPTION: detab - expand tabs int..

Write the program expr , which evaluates a reverse Polish expression from the command line, where each operator or operand is a separate argument. For example, expr 2 3 4 + * evaluates 2 X (3 + 4). Solution by Lars Wirzenius Note: Lars uses EXIT_FAILURE on error. As far as I can tell, this is the only thing which makes this a Category 1, rather than Category 0, solution. /* * Solution to exercis..

Rewrite the routines day_of_year and month_day with pointers instead of indexing. Solutions by Lars Wirzenius and Gregory Pietsch Here's Lars's solution: /* * A solution to exercise 5-9 in K&R2, page 114: * * Rewrite the routines day_of_year and month_day with pointers * instead of indexing. * * Lars Wirzenius */ #include static char daytab[2][13] = { {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, ..

There is no error-checking in day_of_year or month_day. Remedy this defect. Solution by Lars Wirzenius /* * A solution to exercise 5-8 in K&R2, page 112: * * There is no error checking in day_of_year or month_day. Remedy * this defect. * * The error to check for is invalid argument values. That is simple, what's * hard is deciding what to do in case of error. In the real world, I would * use the..

Rewrite readlines to store lines in an array supplied by main , rather than calling alloc to maintain storage. How much faster is the program? Solution by Steven Huang /* K&R Exercise 5-7 */ /* Steven Huang */ #include #include #include #include #define TRUE 1 #define FALSE 0 #define MAXLINES 5000 /* maximum number of lines */ #define MAXLEN 1000 /* maximum length of a line */ char *lineptr[MAXL..