title: How to divide an array into 3 parts with the sum of each part roughly equal
body: <p>I have an arranged array and I want to divide it into 3 parts so that their sum are closest         to each other.</p>
  
  <pre>
  Ex: I have this array:
  
      10, 8, 8, 7, 6, 6, 6, 5
  
  so it'll be divided into 3 part like:
  
      p1 {10,8} sum = 18
      p2 {8,7,6} sum = 21
      p3 {6,6,5} sum = 17
  
  </pre>