Package g0801_0900.s0823_binary_trees_with_factors

Class Solution

  • All Implemented Interfaces:
    
public final class Solution

    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 <code>10<sup>9</sup> + 7</code>.

    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 &lt;= arr.length &lt;= 1000

    • <code>2 <= arri<= 10<sup>9</sup></code>

    • All the values of arr are unique.

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description

    • Field Summary

      Fields 
      Modifier and Type Field Description

    • Constructor Summary

      Constructors 
      Constructor Description
      Solution()

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description

    • Method Summary

      Modifier and Type Method Description
      final Integer numFactoredBinaryTrees(IntArray arr)

      • Methods inherited from class java.lang.Object

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