problem_087.js

// This problem was asked by Uber.
//
// A rule looks like this:
//
// A NE B
//
// This means this means point A is located northeast of point B.
//
// A SW C
//
// means that point A is southwest of C.
//
// Given a list of rules, check if the sum of the rules validate. For example:
//
// A N B
// B NE C
// C N A
//
// does not validate, since A cannot be both north and south of C.
//
// A NW B
// A N B
// is considered valid.