Two Pointers 1 - Medium - Two Sum 2-Input array is sorted - Java

Coding Interviews - Two Sum 2-Input array is sorted (LeetCode)
This interview question is commonly asked by companies like Adobe, Amazon, Google.
We will start with one pointer pointing to the beginning of the array and another pointing at the end. At every step, we will see if the numbers pointed by the two pointers add up to the target sum. If they do, we have found our pair; otherwise, we will do one of two things:

- If the sum of the two numbers pointed by the two pointers is greater than the target sum, this means that we need a pair with a smaller sum. So, to try more pairs, we decrement the end-pointer.
- If the sum of the two numbers pointed by the two pointers is smaller than the target sum, this means that we need a pair with a larger sum. So, to try more pairs, we increment the start-pointer.


Time Complexity -
The time complexity of the above algorithm will be O(N), where ‘N’ is the total number of elements in the given array.

Space Complexity -
The algorithm runs in constant space O(1).

Two pointer playlist
1. Two Sum 2-Input array is sorted - https://youtu.be/dNcK87v3z18
2. Remove Duplicates from Sorted Array - https://youtu.be/yXb4HgYLp2g
3. Squares of a Sorted Array - https://youtu.be/dRr9mLZyz_M
4. Dutch National Flag or Sort Colors - https://youtu.be/Ye48iT5YKpo
5. 3 Sum - https://youtu.be/6xg7ZGfhQdo
6. 3 Sum Smaller - https://youtu.be/VW0zTPMmv9Q
7. 4 Sum - https://youtu.be/co-St3w1mkw
8 . Shortest Unsorted Continuous Subarray - https://youtu.be/Cn4vPghVglU


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