1. Two Sum and 167. Two Sum II - Input array is sorted

https://leetcode.com/problems/two-sum/description/
and
https://leetcode.com/problems/two-sum-ii-input-array-is-sorted/description/

解题思路：

1. 可以用两个loop来解决，也可以用hashset来解决

代码：
class Solution {
public int[] twoSum(int[] nums, int target) {

    int[] res = new int[2];
    if(nums == null) return res;
    for(int i = 0; i < nums.length; i++){
        for(int j = 0; j < nums.length; j++){
            if(i == j) break;
            if(nums[i] + nums[j] == target){
                res[0] = i;
                res[1] = j;
                return res;
            }
        }
    }
    return res;
}

}

class Solution {
public int[] twoSum(int[] numbers, int target) {

    int[] res = new int[2];
    if(numbers == null) return res;
    for(int i = 0; i < numbers.length; i++){
        for(int j = i + 1; j < numbers.length; j++){
            if(numbers[i] + numbers[j] == target){
                res[0] = i + 1;
                res[1] = j + 1;
                return res;
            }
        }
    }
    return res;
}

}