Medium
Given an array of positive integers nums
, remove the smallest subarray (possibly empty) such that the sum of the remaining elements is divisible by p
. It is not allowed to remove the whole array.
Return the length of the smallest subarray that you need to remove, or -1
if it’s impossible.
A subarray is defined as a contiguous block of elements in the array.
Example 1:
Input: nums = [3,1,4,2], p = 6
Output: 1
Explanation: The sum of the elements in nums is 10, which is not divisible by 6. We can remove the subarray [4], and the sum of the remaining elements is 6, which is divisible by 6.
Example 2:
Input: nums = [6,3,5,2], p = 9
Output: 2
Explanation: We cannot remove a single element to get a sum divisible by 9. The best way is to remove the subarray [5,2], leaving us with [6,3] with sum 9.
Example 3:
Input: nums = [1,2,3], p = 3
Output: 0
Explanation: Here the sum is 6. which is already divisible by 3. Thus we do not need to remove anything.
Constraints:
1 <= nums.length <= 105
1 <= nums[i] <= 109
1 <= p <= 109
class Solution {
fun minSubarray(nums: IntArray, p: Int): Int {
val hmp = HashMap<Int, Int>()
val n = nums.size
var target = 0
var sum = 0
for (num in nums) {
target = (num + target) % p
}
if (target == 0) {
return 0
}
hmp[0] = -1
var ans = n
for (i in 0 until n) {
sum = (sum + nums[i]) % p
val key = (sum - target + p) % p
if (hmp.containsKey(key)) {
ans = Math.min(ans, i - hmp[key]!!)
}
hmp[sum % p] = i
}
return if (ans < n) {
ans
} else {
-1
}
}
}