LeetCode in Kotlin
974. Subarray Sums Divisible by K
Medium
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.
Example 1:
Input: nums = [4,5,0,-2,-3,1], k = 5
Output: 7
Explanation: 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 * 104-104 <= nums[i] <= 1042 <= k <= 104
Solution
class Solution {
fun subarraysDivByK(nums: IntArray, k: Int): Int {
val map = IntArray(k)
var ans = 0
var sum = 0
map[0] = 1
for (num in nums) {
sum += num
var temp = sum % k
if (temp < 0) {
temp += k
}
ans += map[temp]++
}
return ans
}
}