1 /*
2  * 2-4. Write an alternate version of squeeze(s1, s2) that deletes each
3  * character in s1 that matches any character in the string s2.
4  */
5 #include <stdio.h>
6 
7 void squeeze(char s1[], char s2[]);
8 char * strchr(const char *s, int c);
9 
10 main () {
11 	char haystack[] = "The quick brown fox jumped over the lazy dog.";
12 	squeeze(haystack, "a");
13 	printf("a: %s\n", haystack);
14 	squeeze(haystack, "b");
15 	printf("b: %s\n", haystack);
16 	squeeze(haystack, "c");
17 	printf("c: %s\n", haystack);
18 	squeeze(haystack, "d");
19 	printf("d: %s\n", haystack);
20 	squeeze(haystack, "e");
21 	printf("e: %s\n", haystack);
22 	squeeze(haystack, "f");
23 	printf("f: %s\n", haystack);
24 	squeeze(haystack, "g");
25 	printf("g: %s\n", haystack);
26 	squeeze(haystack, "h");
27 	printf("h: %s\n", haystack);
28 	squeeze(haystack, "i");
29 	printf("i: %s\n", haystack);
30 	squeeze(haystack, "j");
31 	printf("j: %s\n", haystack);
32 	squeeze(haystack, "k");
33 	printf("k: %s\n", haystack);
34 }
35 
36 void squeeze(char s1[], char s2[]) {
37 	int i, j;
38 	for (i = j = 0; s1[i] != '\0'; ++i) {
39 		if (!strchr(s2, s1[i])) {
40 			s1[j++] = s1[i];
41 		}
42 	}
43 	s1[j] = '\0';
44 }
45 
46 char * strchr(const char *s, int c) {
47 	int i;
48 	for (i = 0; *(s+i) != c; ++i)
49 		if (*(s+i) == '\0')
50 			return 0;
51 	return s+i;
52 }