Question

I have to Implement function rps() that takes the choice ('R', 'P', or 'S') of player 1 and the choice of player 2, and returns -1 if player 1 wins, 1 if player 2 wins, or 0 if there is a tie. I wrote out my code for comparison but its not working properly, should I implement a set or dictionary to make it properly work?

Answer 1

if it's java code, upload it.. I'd take a look at it.

Answer 2

I would use a dictionary

let
p1 is the choice of player 1
p2 is the choice of player 2

RPS_outcome ={SS:0, SP:-1, SR:1, PS:1, PP:0, PR:-1, RS:-1, RP:1, RR:0)
then you can return RPS_outcome[p1+p2]

Answer 3

another option is of course to write it all out in if else statements
```
if p1 == p2:
return 0
elif p1 == 'S':
if p2 == 'P':
return -1
else:
return 1
elif p1 == 'P':
if p2 == 'R':
return -1
else:
return 1
elif p1 == 'R':
if p2 == 'S':
return -1
else:
return 1
```

Answer 4

does java have 'dictionaries'?

Answer 5

@abster

Answer 6

I thought this course uses python, since the title is
MIT 6.189 A Gentle Introduction to Programming Using Python (OCW) Subtopics

I hardly know any Java, so I don't know if java has dictionaries
However googling it gives me for instance
http://docs.oracle.com/javase/7/docs/api/java/util/Dictionary.html

So I think java indeed has dictionaries

Answer 7

thanks abster. I wasn't aware that this was in the python sub-catagory.. all the questions seem to meld into the same bucket lol.

Answer 8

Yah, a subcategory on a Java course (OCW) would be nice