Leetcode 167. Two Sum II - Input Array Is Sorted

by. Jongwon Lee | 152 Views (135 Uniq Views) | almost 3 years ago
#Leecode #CodingChallenge #Algorithm
Leetcode 167. Two Sum II - Input Array Is Sorted
A very clever solution that uses two pointers (indices) from the start and the end.
Compare the sum with the "target" and this naturally returns the two indices.

class Solution(object):
    def twoSum(self, numbers, target):
        l, r = 0, len(numbers) - 1 #two indices from start and end

        while l < r:
            curSum = numbers[l] + numbers[r]

            if curSum > target:
                r -= 1
            elif curSum < target:
                l += 1
            else:
                return [l + 1, r + 1]

#source: neetcode