tcpl_ex-2-4.c

/*
 * Exercise 2-4. Write an alternative version of squeeze(s1,s2) that deletes 
 * each character in s1 that matches any character in the string s2.  
 */
#include <stdio.h>
#include <stdlib.h>

void squeeze(char s1[], const char s2[]);
int indexof(const char s[], char c);

/* Return the index of character c in string s, if not found return -1
 * 
 * @param s const char*
 * @param c char
 *
 * @return the index if found, otherwise -1
 *
 */
int indexof(const char s[], char c) {
	int i = 0;
	while ('\0' != s[i]) {
		if (c == s[i])
			return i;
		i++;
	}
	return -1;
}


/* Deletes each character in s1 that matches any character in the string s2. 
 * 
 * @param s1 char*
 * @param s2 const char*
 */

void squeeze(char s1[], const char s2[]) {
	int i, j;
	for (i = j = 0; '\0' != s1[i]; i++) {
		if (indexof(s2, s1[i]) == -1)
			s1[j++] = s1[i];
	}
	s1[j] = '\0';
}


int main(void) {
	char s1[] = "asdfasdfasdf";

	char s2[] = "asdf";

	char r[] = "";


	squeeze(s1, s2);
	if (strcmp(r, s1) == 0)
		printf("expected -> %s actual -> %s: equal\n", r, s1);
	else
		printf("expected -> %s actual -> %s: not equal\n", r, s1);

	return 0;
}