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

about this snippet

This is the twosum snippet in Java — a classic LeetCode interview problem. Type it through to build the muscle memory you need to write it under interview pressure. DeveloperType scores you on net WPM and accuracy and only counts runs above 95% accuracy on the leaderboard, so practice rewards precision, not speed alone.

public int[] twoSum(int[] nums, int target) {
    Map<Integer, Integer> seen = new HashMap<>();
    for (int i = 0; i < nums.length; i++) {
        int need = target - nums[i];
        if (seen.containsKey(need)) {
            return new int[]{seen.get(need), i};
        }
        seen.put(nums[i], i);
    }
    return new int[]{};
}