Write the function strrindex(s, t) , which returns the position of the rightmost occurrence of t in s, or -1 if there is none.

/*strrindex:returns rightmost index of t in s, -1 if none */
int strrindex(char s[], char t[]){
    int i, j, k, pos;
  
    pos = -1;
    for(i = 0; s[i] != '\0'; i++){
       for(j = i, k =0; t[k] != '\0' && s[j] == t[k]; j++, k++)
              ;
       if( k > 0 && t[k] == '\0')
           pos = i;
    }
    return pos;
}


/*A more efficient solution to the same problem */
#include <string.h>
/*strrindex :returns rightmost index of t in s , -1 if none */
int strrindex(char s[], char t[]){
    int i, j, k;

    for (i = strlen(s) - strlen(t); i >= 0; i--){
       for (j =1, k=0; t[k] != '\0' && s[j] == t[k];j++, k++)
                  ;
       if (k > 0 && t[k] == '\0')
            return i;
    }
    return -1;
}