#include <stdio.h>
#include <stddef.h>

char *mystrpbrk(const char *s, const char *e, const char t[]) {
	for ( ; s < e; ++s) {
		const char *p;
		for (p = t; *p; ++p)
			if (*s == *p)
		return (char *)s;
	}
	return NULL;
}

char *mystrrpbrk(const char *s, const char *e, const char t[]) {
	while (s < e) {
		const char *p, c = *--e;
		for (p = t; *p; ++p)
			if (c == *p)
		return (char *)e;
	}
	return NULL;
}

int main(void) {
	const char s[] = "EDCBABCDE";
	const char *e = s + sizeof s - 1;
	const char *t = "BCD", *p;
	
	if ((p = mystrrpbrk(s, e, t)) != NULL)
		printf("%d\n", (int)(p - s + 1));
	if ((p = mystrpbrk(s + 3, e, t)) != NULL)
		printf("%d\n", (int)(p - s + 1));
	if ((p = mystrpbrk(s + 4, s + 6, t)) != NULL)
		printf("%d\n", (int)(p - s + 1));
		
	return 0;
}