✡ leetcode 167. Two Sum II - Input array is sorted 求两数相加等于一个数的位置 --------- java

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. Please note that your returned answers (both index1 and index2) are not zero-based.

You may assume that each input would have exactly one solution.

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

 

 

第一题就是两数相加的题，其实可以用同一种解法。

 

这算法很基础，也没什么特殊的点。

 

public class Solution {
    public int[] twoSum(int[] numbers, int target) {
        int len = numbers.length;
        int left = 0;
        int right = len - 1;
        int[] result = new int[2];
        while (left < right){
            if (numbers[left] + numbers[right] <  target){
                left++;
            } else if (numbers[left] + numbers[right] > target){
                right--;
            } else {
                result[0] = left + 1;
                result[1] = right + 1;
                break;
            }
        }
        return result;
    }
}