Given an array of integers, return true if it contains a 2, 7, 1 pattern -- a value, followed by the value plus 5, followed by the initial value minus 1. So, 2,7,1 is such a pattern because 7 is 5+2 and 1 is 2-1. 3,8,2 is also such a pattern.
Additionally the 271 counts even if the "1" differs by 2 or less from the correct value.
This exercise was converted to PLM from the excellent exercising site http://codingbat.com/