Two Sum II - Input Array Is Sorted
Given a 1-indexed array of integers numbers that is already sorted in non-decreasing order, find two numbers such that they add up to a specific target number. Let these two numbers be numbers[index1] and numbers[index2] where 1 <= index1 < index2 <= numbers.length.
Return[index1, index2] as an integer array of length 2.
The tests are generated such that there is exactly one solution. You may not use the same element twice.
Your solution must use only constant extra space.
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. We return [1, 2].
Constraints:
2 <= numbers.length <= 3 * 104-1000 <= numbers[i] <= 1000numbersis sorted in non-decreasing order.-1000 <= target <= 1000- The tests are generated such that there is exactly one solution.
Golang Solution:
func twoSum(numbers []int, target int) []int {
l := 0
h := len(numbers) - 1
for l < h {
if (numbers[l] + numbers[h]) == target {
return []int{l+1,h+1}
} else if (numbers[l] + numbers[h]) < target {
l++;
}
if (numbers[l] + numbers[h]) > target {
h--;
}
}
return nil
}Result Image:
