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 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 and Description
Solution()

Method Summary

Modifier and Type	Method and Description
int	numOfSubarrays(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

numOfSubarrays

public int numOfSubarrays(int[] arr)