LeetCode-1. Two Sum

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.

Example:

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

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

public class Solution {
    public int[] twoSum(int[] nums, int target) {
        if (nums == null)
            return new int[0];
        
        for (int i=0; i<nums.length; i++) {
            for (int j=i+1; j<nums.length; j++) {
                if (nums[i]+nums[j] == target)
                    return new int[]{i, j};
            }
        }
        return new int[0];
    }
}