Two Sum II - Input Array Is Sorted

Easy

Two Sum II - Input Array Is Sorted

EasyCategory: Two PointersAcceptance: 89%

Problem Statement

Given a 1-indexed array of integers `numbers` that is already sorted in non-decreasing order, find two numbers such that they add up to a specific `target` number. Return the indices of the two numbers, `[index1, index2]`, added by one as an integer array `[index1, index2]` where `1 <= index1 < index2 <= numbers.length`. You must solve the problem using constant extra space O(1).

Examples

Example 1:

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. We return [1, 2].

Example 2:

Input: numbers = [2,3,4], target = 6

Output: [1, 3]

Explanation: The sum of 2 and 4 is 6. Therefore index1 = 1, index2 = 3. We return [1, 3].

Constraints

2 <= numbers.length <= 3 * 10^4
-1000 <= numbers[i] <= 1000
numbers is sorted in non-decreasing order.
-1000 <= target <= 1000
The tests are generated such that there is exactly one solution.

Solution Editor

Input:numbers = [2,7,11,15], target = 9

Expected Output:[1, 2]