#include <stdio.h>

char *StrRChar(char *s, const char c) {
	char *p = s;
	
	while (*s != '\0')
		s++;
	while (*s != c && p < s)
		s--;
	if (*s == c)
		return (s);
	else
		return (NULL);
}

void main(void)
{
	char *p;
	char c;
	char str[ ] = "abcdefghijklmnopqrstuvwxyz";
	
	printf("str = %s\n", str);
	printf(" Please enter one letter\t");
	scanf("%c", &c);
	
	p = StrRChar(str, c);
	printf("StrRChar(str,'%c');\n", c);
	if (p != NULL)
		printf("%s\n", p);
	else
		printf(""can not find!\n");
}