You are given an array of transactions transactions where transactions[i] = [fromi, toi, amounti] indicates that the person with ID = fromi gave amounti $ to the person with ID = toi.
Return the minimum number of transactions required to settle the debt.
The question below is similar to an N way partition problem (instead of 3 way partition problem
Then the problem can be converted to the following:
Given N accounts/persons who have non zero amounts,find the M = max number of sets where each set s has sum(s)==0.Each of these sets must be min_set. In other words, min_set CANNOT be divided to setA and setB where sum(setA) == sum(setB)==0.
