Package g0801_0900.s0823_binary_trees_with_factors

Class Solution

java.lang.Object
g0801_0900.s0823_binary_trees_with_factors.Solution
public class Solution extends java.lang.Object
823 - Binary Trees With Factors.

Medium

Given an array of unique integers, arr, where each integer arr[i] is strictly greater than 1.

We make a binary tree using these integers, and each number may be used for any number of times. Each non-leaf node’s value should be equal to the product of the values of its children.

Return the number of binary trees we can make. The answer may be too large so return the answer modulo 109 + 7.

Example 1:

Input: arr = [2,4]

Output: 3

Explanation: We can make these trees: [2], [4], [4, 2, 2]

Example 2:

Input: arr = [2,4,5,10]

Output: 7

Explanation: We can make these trees: [2], [4], [5], [10], [4, 2, 2], [10, 2, 5], [10, 5, 2].

Constraints:

  • 1 <= arr.length <= 1000
  • 2 <= arr[i] <= 109
  • All the values of arr are unique.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

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

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • numFactoredBinaryTrees

      public int numFactoredBinaryTrees(int[] arr)