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Java-based LeetCode algorithm problem solutions, regularly updated

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package g2301_2400.s2395_find_subarrays_with_equal_sum;

// #Easy #Array #Hash_Table #2022_09_14_Time_0_ms_(100.00%)_Space_40.3_MB_(93.74%)

import java.util.HashSet;
import java.util.Set;

/**
 * 2395 - Find Subarrays With Equal Sum\.
 *
 * Easy
 *
 * Given a **0-indexed** integer array `nums`, determine whether there exist **two** subarrays of length `2` with **equal** sum. Note that the two subarrays must begin at **different** indices.
 *
 * Return `true` _if these subarrays exist, and_ `false` _otherwise._
 *
 * A **subarray** is a contiguous non-empty sequence of elements within an array.
 *
 * **Example 1:**
 *
 * **Input:** nums = [4,2,4]
 *
 * **Output:** true
 *
 * **Explanation:** The subarrays with elements [4,2] and [2,4] have the same sum of 6. 
 *
 * **Example 2:**
 *
 * **Input:** nums = [1,2,3,4,5]
 *
 * **Output:** false
 *
 * **Explanation:** No two subarrays of size 2 have the same sum. 
 *
 * **Example 3:**
 *
 * **Input:** nums = [0,0,0]
 *
 * **Output:** true
 *
 * **Explanation:** The subarrays [nums[0],nums[1]] and [nums[1],nums[2]] have the same sum of 0.
 *
 * Note that even though the subarrays have the same content, the two subarrays are considered different because they are in different positions in the original array. 
 *
 * **Constraints:**
 *
 * *   `2 <= nums.length <= 1000`
 * *   -10⁹ <= nums[i] <= 10⁹
**/
public class Solution {
    public boolean findSubarrays(int[] nums) {
        Set set = new HashSet<>();
        for (int i = 1; i < nums.length; ++i) {
            if (!set.add(nums[i] + nums[i - 1])) {
                return true;
            }
        }
        return false;
    }
}