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Mayukh Datta

Two Sum II LeetCode Solution

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 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.

Example 2:

Input: numbers = [2,3,4], target = 6 Output: [1,3]

Example 3:

Input: numbers = [-1,0], target = -1 Output: [1,2]

Constraints:

  • 2 <= nums.length <= 3 * 104
  • -1000 <= nums[i] <= 1000
  • nums is sorted in increasing order.
  • -1000 <= target <= 1000

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

Solution
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