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

Solution.java

public class Solution {
    
    class Entry {
        int pos;
        int val;
        Entry(int pos, int val) {
            this.pos = pos;
            this.val = val;
        }
    }
    
    public int[] twoSum(int[] nums, int target) {
        
        ArrayList<Entry> data = new ArrayList<Entry>();
        int pos = 0;
        for(int num : nums) {
            data.add(new Entry(pos, num));
            pos++;
        }
        
        Collections.sort(data, new Comparator<Entry>() {
            public int compare(Entry o1, Entry o2) {
                return o1.val - o2.val;
            }
        });
        
        int i = 0, j = data.size() - 1;
        while(i < j && data.get(i).val + data.get(j).val != target) {
            if(data.get(i).val + data.get(j).val < target) {
                i++;
            } else {
                j--;
            }
        }
        
        return new int[] {data.get(i).pos, data.get(j).pos};
    }
}