Subarray Sums Divisible by K

arrayhash tableprefix sum

Problem Statement

Given an integer array nums and an integer k , return the number of non-empty subarrays that have a sum divisible by k .

A subarray is a contiguous part of an array.

Examples

Example 1

Input: nums = [4,5,0,-2,-3,1], k = 5
Output: 7
There are 7 subarrays with a sum divisible by k = 5:
[4, 5, 0, -2, -3, 1], [5], [5, 0], [5, 0, -2, -3], [0], [0, -2, -3], [-2, -3]

Example 2

Input: nums = [5], k = 9
Output: 0

Constraints

1 <= nums.length <= 3 * 10 ^4

-10 ^4 <= nums[i] <= 10 ^4

2 <= k <= 10 ^4

🤔

Medium

Difficulty

Topic Info

ModuleDSA

CategoryArray

Sub-topicHash Table