C_PRG_LANG_EX_4.1

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <limits.h>

#define ABS(n) n >= 0 ? n : -n

int strrindex(char *s, char *t)
{
    int r_index = -1;
    char *start = s;
    while(*s)
    {
        if (*s == *t)
        {
            int pos = 0;
            for(; *(s + pos) != '\0' && *(t + pos) != '\0'
                && *(s + pos) == *(t + pos);)
                pos++;

            if (*(t + pos) == '\0')
                r_index = s - start;
        }
        s++;
    }
    return r_index;
}


int main(void)
{
    char *str = "qwe qwe rasrawdabc asdawd abcqwe";
    char *search = "qwe";
    printf("%i", strrindex(str, search));

    return 0;
}