167 - Two Sum II (Input Array Is Sorted)

Details

Key	Value
Link	https://leetcode.com/problems/two-sum-ii-input-array-is-sorted/
Language	Python 3
Runtime	176 ms, faster than 50.98% of Python3 online submissions for Two Sum II - Input Array Is Sorted
Memory Usage	14.8 MB, less than 89.05% of Python3 online submissions for Two Sum II - Input Array Is Sorted
Datastructures	List[int]
Algorithms	Two Pointers

Procedure

1. Left pointer starts at first index Right pointer starts ar last index
2. Until the two pointers meet in the middle...
3. If sum of left and right matches the target we're done
4. If sum of left and right is less, increase left pointer
5. If sum of left and right is more, decrease right pointer

Code

class Solution:
    def twoSum(self, numbers: List[int], target: int) -> List[int]:
        left, right = 0, len(numbers) - 1
        
        while left < right:
            if numbers[left] + numbers[right] == target:
                return [left+1, right+1]
            elif numbers[left] + numbers[right] < target:
                left += 1
            else:
                right -= 1