Given a non-empty vector x with integer elements. x shall be called balance vector if one can split the elements of x into two groups which are in total equal. e.g.
x=[1,1] balance vector because 1=1
x=[1,7] non-balance vector because 1~=7
x=[2,3,5] balance vector because 2+3=5
Write a function that returns true or false depending if the given vector is a balance vector or not!