Mcq doubt o n cp

#1

you are given a sequence A[1], A[2], …, A[N] . Find the max-sum subarray in the range [L,R].

We need to answer Q queries each with two inputs L and R. (SPOJ GSS1)

We wish to solve this problem using a segment tree.

At each node of the tree that represents the segment [x…y] of the array we keep :

  1. SUM — sum of all numbers in this segment
  2. BEST — maximal sum of any subsegment of this segment
  3. BestLeft - maximal sum of any subsegment [i…j] of this segment, and i == x
  4. BestRight - maximal sum of any subsegment [i…j] of this segment, and j == y
    Say node p is the parent of node c1(left child) and c2(right child) in the segment tree.

choose the correct option :

All of these are correct…

p.SUM = c1.SUM + c2.SUM

p.BEST = max(max(c1.BEST, c2.BEST) , c1.BestRight + c2.BestLeft)

p.BestLeft = max(c1.BestLeft, c1.SUM + c2.BestLeft)

Please expalin me the output of thequestion