Please help me with this C++ assignment!

RIGHTMOST CHAR

CHALLENGE DESCRIPTION:

You are given a string 'S' and a character 't'. Print out the position of the rightmost occurrence of 't' (case matters) in 'S' or -1 if there is none. The position to be printed out is zero based.

INPUT SAMPLE:

The first argument will be a path to a filename (e.g. the program was executed with >>> ./a.out input.txt <<<<< ), containing a string and a character, comma delimited, one per line. Ignore all empty lines in the input file. E.g.

Hello World,r Hello CodeEval,E 

OUTPUT SAMPLE:

Print out the zero based position of the character 't' in string 'S', one per line. Do NOT print out empty lines between your output. E.g.

8 10