Two sum II¶
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]
Solution¶
from typing import List
def two_sum(nums: List[int], target: int) -> List[int]:
left = 0
right = len(nums) - 1
while left < right:
total = nums[left] + nums[right]
if total < target:
left += 1
elif total > target:
right -= 1
else:
return [left + 1, right + 1]
two_sum([2, 3, 4], 6)
[1, 3]