1. Two Sum | LeetCode | Top Interview 150 | Coding Questions

Problem Link

https://leetcode.com/problems/two-sum/

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Detailed Step-by-Step Explanation

https://leetcode.com/problems/two-sum/solutions/7498090/most-optimal-solution-beats-200-hashmap-bya71

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Solution

class Solution {
    public int[] twoSum(int[] nums, int target) {

        Map<Integer, Integer> map = new HashMap<>();

        for (int i = 0; i < nums.length; i++) {
            int compliment = target - nums[i];

            if (map.containsKey(compliment)) {
                return new int[] { map.get(compliment), i };
            }

            map.put(nums[i], i);
        }

        return new int[] {};
    }
}