Leetcode : Two Sum 2

167. Two Sum 2 - Input array is sorted

• 난이도 : Easy

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.

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.

• Example:

Input: numbers = [2,7,11,15], target = 9  
Output: [1,2]  
Explanation: The sum of 2 and 7 is 9. Therefore index1 = 1, index2 = 2.

코드구현

class Solution {
    public int[] twoSum(int[] numbers, int target) {
        int[] answer = {0,0};
        for(int i=0;i<numbers.length;i++){
            for(int j=i+1;j<numbers.length;j++){
                int sum = numbers[i]+numbers[j];
                if (sum == target){
                    answer[0] = i+1;
                    answer[1] = j+1;
                    break;
                }
            }
        }
        return answer;
    }
}

요약

• 이중 포문을 이용하여, target이 되는 값을 찾는다.
• j=i+1 부터 연산하여, 중복연산이 일어나는 경우를 막는다.

 

문제

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

Two Sum II - Input array is sorted - LeetCode