class Solution {

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

int n = nums.length;

for (int i = 0; i < n; ++i) {

for (int j = i + 1; j < n; ++j) {

if (nums[i] + nums[j] == target) {

return new int[]{i, j};

}

}

}

return new int[0];

}

}

class Solution {

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

Map<Integer, Integer> hashtable = new HashMap<Integer, Integer>();

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

if (hashtable.containsKey(target - nums[i])) {

return new int[]{hashtable.get(target - nums[i]), i};

}

hashtable.put(nums[i], i);

}

return new int[0];

}

}