LeetCode 编程练习 - Two Sum II - Input array is sorted学习心得

题目：

     Given an array of integers that is alreadysorted 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. Please note that your returned answers (both index1 and
index2) are not zero-based.

     You may assume that each input would haveexactly one
solution and you may not use thesame element twice.

      Input: numbers={2, 7, 11, 15}, target=9
     Output: index1=1, index2=2

      给定一个已按升序排序的整数数组，查找两个数字，他们加起来为一个特定的目标数，Index2应该返回；两个数字的索引，index1必须小于index2，返回的答案index1和index2并非从0开始，假设每个输入只有一个解决方案，不能重复使用相同的元素两次。

思路：

   定义两个长度变量i和j，分别是数组的开头和结尾，然后将它们所指的数相加与目标数对比，若相等，则存到新数组中退出，若相加和大于目标数，则j-1，若和小于目标数，则i+1。



    运行结果：