Leetcode 167:two Sum ii-input Array is sorted

Both Sum ii-input array is sortedTotal Accepted: 441 Total Submissions: 1017

Given an array of integers that's already sorted in ascending order, find, numbers such, they add up to a Specific target number.

The function twosum should return indices of the numbers such that they add up to the target, where index1 must is Les S than Index2. Please note that your returned answers (both Index1 and INDEX2) is not zero-based.

You may assume this each input would has exactly one solution.

Input: numbers={2, 7, one, target=9
Output: index1=1, index2=2

Analysis

greedy algorithm, two pointer move to the middle.

public class Solution {public    int[] Twosum (int[] numbers, int target) {        if (Numbers==null | | Numbers.length < 1 ) return null;        int i=0, j=numbers.length-1;                while (i<j) {            int x = numbers[i] + numbers[j];            if (x<target) {                ++i;            } else if (x>target) {                --j;            } else {                return new int[]{i+1, j+1};            }        }        return null;}    }

Leetcode 167:two Sum ii-input Array is sorted