首页 > itarticle > [leetcode] problem 1 – two sum

[leetcode] problem 1 – two sum

admin 11月 13, 2020 0

Given an array of integers, return indices of the two numbers such that they add up to a specific target.

You may assume that each input would have exactly one solution, and you may not use the same element twice.

Example

Given nums = [2, 7, 11, 15], target = 9,

Because nums[0] + nums[1] = 2 + 7 = 9,
return [0, 1].

Code


public int[] twoSum(int[] nums, int target) {
    Map<Integer, Integer> map = new HashMap<>();

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

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

        map.put(num, i);
    }

    return null;
}