Given scores of N athletes, find their relative ranks and the people with the top three highest scores, who will be awarded medals: "Gold Medal", "Silver Medal" and "Bronze Medal".

class Solution {
    public String[] findRelativeRanks(int[] nums) {
        if(nums == null || nums.length == 0)
            return new String[0];

        TreeMap<Integer, Integer> map = new TreeMap<Integer, Integer>(new Comparator<Integer>(){
            public int compare(Integer i1, Integer i2) {
                return i2 - i1;
            }
        });
        for(int i = 0; i < nums.length; i++) {
            map.put(nums[i], i);
        }

        String[] res = new String[nums.length];
        int i = 0;
        for(Map.Entry<Integer, Integer> entry: map.entrySet()) {
            if(i == 0) {
                res[entry.getValue()] = "Gold Medal";
            } else if(i == 1) {
                res[entry.getValue()] = "Silver Medal";
            } else if(i == 2) {
                res[entry.getValue()] = "Bronze Medal";
            } else {
                res[entry.getValue()] = String.valueOf(i + 1);
            }
            i++;
        }

        return res;
    }
}