Leetcode-167. Two Sum II - Input array is sorted

地址：

描述：

Given an array of integers that is already sorted in ascending order, find two numbers such that they add up to a specific target number.

The function twoSum should return indices of the two numbers such that they add up to the target, where index1 must be less than index2.

給定一個有序整型數組和一個整數 target，在其中尋找兩個元素，使其和爲 target，返回這兩個數的索引。

Note:

• Your returned answers (both index1 and index2) are not zero-based.
• You may assume that each input would have exactly one solution and you may not use the same element twice.

 

示例：

如: numbers = [2,7,11,15], target = 9
Output: [1,2]
Explanation: The sum of 2 and 7 is 9. Therefore index1 = 1, index2 = 2.
例如：2和7的和是9，返回二、7的所1和2（索引從1開始計算的）

方法：

   public int[] twoSum(int[] numbers, int target) {
        int l = 0;
        int r = numbers.length - 1;
        while (l < r) {
            if (numbers[l] + numbers[r] == target) {
                break;
            } else if (numbers[l] + numbers[r] < target) {
                l++;
            } else {
                r--;
            }
        }

        return new int[]{l + 1, r + 1};

    }