Package g1501_1600.s1524_number_of_sub_arrays_with_odd_sum

Class Solution

java.lang.Object
g1501_1600.s1524_number_of_sub_arrays_with_odd_sum.Solution
public class Solution extends java.lang.Object
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 109 + 7.

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:

  • 1 <= arr.length <= 105
  • 1 <= arr[i] <= 100

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    numOfSubarrays(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

    • numOfSubarrays

      public int numOfSubarrays(int[] arr)