g1101_1200.s1130_minimum_cost_tree_from_leaf_values

Class Solution

java.lang.Object

g1101_1200.s1130_minimum_cost_tree_from_leaf_values.Solution

public class Solution
extends Object

1130 - Minimum Cost Tree From Leaf Values.

Medium

Given an array arr of positive integers, consider all binary trees such that:

• Each node has either 0 or 2 children;
• The values of arr correspond to the values of each leaf in an in-order traversal of the tree.
• The value of each non-leaf node is equal to the product of the largest leaf value in its left and right subtree, respectively.

Among all possible binary trees considered, return the smallest possible sum of the values of each non-leaf node. It is guaranteed this sum fits into a 32-bit integer.

A node is a leaf if and only if it has zero children.

Example 1:

Input: arr = [6,2,4]

Output: 32

Explanation: There are two possible trees shown. The first has a non-leaf node sum 36, and the second has non-leaf node sum 32.

Example 2:

Input: arr = [4,11]

Output: 44

Constraints:

• 2 <= arr.length <= 40
• 1 <= arr[i] <= 15
• It is guaranteed that the answer fits into a 32-bit signed integer (i.e., it is less than 2³¹).

Constructor Summary

Constructors

Constructor and Description
Solution()

Method Summary

Modifier and Type	Method and Description
int	mctFromLeafValues(int[] arr)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Solution

public Solution()

Method Detail

mctFromLeafValues

public int mctFromLeafValues(int[] arr)