solution.java

import java.util.HashMap;

class Solution {
    public int minSubarray(int[] nums, int p) {
        long totalSum = 0;
        for (int num : nums) {
            totalSum += num;
        }

        // Find remainder when total sum is divided by p
        int rem = (int) (totalSum % p);
        if (rem == 0)
            return 0; // If remainder is 0, no subarray needs to be removed

        HashMap<Integer, Integer> prefixMod = new HashMap<>();
        prefixMod.put(0, -1); // Initialize to handle full prefix
        long prefixSum = 0;
        int minLength = nums.length;

        for (int i = 0; i < nums.length; ++i) {
            prefixSum += nums[i];
            int currentMod = (int) (prefixSum % p);
            int targetMod = (currentMod - rem + p) % p;

            if (prefixMod.containsKey(targetMod)) {
                minLength = Math.min(minLength, i - prefixMod.get(targetMod));
            }

            prefixMod.put(currentMod, i);
        }

        return minLength == nums.length ? -1 : minLength;
    }
}