COMPUTER SCIENCE: POINTERS

PA202/tools.c

// TODO - Implement the functions in this file #include <stdlib.h> #include <ctype.h> void word_reverse( char* str ){ /* ROLE Reverses the order of the character in the string. Does not modify the end of string marker '\0'. PARAMETERS str - the string to reverse */ // THE CODE INSIDE IS ONLY A TEMPLATE - REPLACE IT ALL! while(*str){ *str = '*'; str++; } } int is_separator( char data ){ /* ROLE Tests if the character passed as parameter is a separator; i.e. something different than a letter or digit. RETURNS 1 - if data is a separator 0 - otherwise PARAMETERS data - the character to test */ return ( !isalnum(data) ); } int words_initialize( char* str, char* words[], int maxwords ){ /* ROLE Parses the string str and identify each word in it. Words are separated by any character which makes the is_separator function returns true. The address of the first character of each word in the string str, is stored as a pointer in the array words. When we find the end of the word we just added in the string str, we modify it so that the next character becomes '\0'. We are not able to handle more than maxwords words and subsequent ones will be ignored. Our function will return the number of words it found which also indicates how many of the maxwords elements in the array words are meaningful. RETURNS the number of words identified in the string input. If any parameters are inappropriate, return 0 PARAMETERS input - string in which we will identify words words - an array of pointer on strings which will be the words we have identified maxwords - the size of the words array of pointers */ words[0] = str; return(1); } void word_handle_marker(char* str){ // WORKING FUNCTION - JUST DOCUMENT :) - GIFT /* ROLE Replaces the end of string marker '\0' by a space ' ' PARAMETERS str - the string to modify */ if(!str) return; // handling parameter being a NULL string while(*str){ str++; } *str = ' '; } void words_modify(char* str){ const int MAXWORDS = 256; char* allwords[MAXWORDS]; int i; int nbwords; if(!str) return; // handling parameter being a NULL string /* initialize all pointers in allwords to NULL */ for(i=0; i < MAXWORDS ; i++) allwords[i] = NULL; nbwords = words_initialize(str, allwords, MAXWORDS); for(i=0 ; i < nbwords ; i++){ word_reverse(allwords[i]); } for(i=0 ; i < (nbwords-1) ; i++){ word_handle_marker(allwords[i]); } }