Package g1501_1600.s1524_number_of_sub_arrays_with_odd_sum

Class Solution

  • All Implemented Interfaces:
    
public final class Solution

    1524 - Number of Sub-arrays With Odd Sum.

    Medium

    Given an array of integers arr, return the number of subarrays with an odd sum.

    Since the answer can be very large, return it modulo <code>10<sup>9</sup> + 7</code>.

    Example 1:

    Input: arr = 1,3,5

    Output: 4

    Explanation: All subarrays are [1,1,3,1,3,5,3,3,5,5]

    All sub-arrays sum are 1,4,9,3,8,5.

    Odd sums are 1,9,3,5 so the answer is 4.

    Example 2:

    Input: arr = 2,4,6

    Output: 0

    Explanation: All subarrays are [2,2,4,2,4,6,4,4,6,6]

    All sub-arrays sum are 2,6,12,4,10,6.

    All sub-arrays have even sum and the answer is 0.

    Example 3:

    Input: arr = 1,2,3,4,5,6,7

    Output: 16

    Constraints:

    • <code>1 <= arr.length <= 10<sup>5</sup></code>

    • 1 &lt;= arr[i] &lt;= 100

    • 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 numOfSubarrays(IntArray arr)

      • Methods inherited from class java.lang.Object

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