1. Two Pointers

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Example 1:

Input: nums = [2, 7, 11, 15], target = 9

Output: [0, 1]

Explanation: The numbers at indices 0 and 1 (2 and 7) add up to 9.

Example 2:

Input: nums = [2, 7, 11, 15], target = 10

Output: [-1, -1]

Explanation: No two numbers in the array add up to 10.

Example 3:

Input: nums = [3, 3], target = 6

Output: [0, 1]

Explanation: The numbers at indices 0 and 1 (3 and 3) add up to 6.

Example 4:

Input: nums = [-1,0], target = -1

Output: [0, 1]

Explanation: The numbers at indices 0 and 1 (-1 and 0) add up to -1.

Example 5:

Input: nums = [5], target = 5

Output: [-1, -1]

Explanation: Needs 2 numbers to sum to target.

Constraints:

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Time Complexity

O(n)

Space Complexity

O(1)

1. Two Pointers

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Example 1:

Example 2:

Example 3:

Example 4:

Example 5:

Constraints:

Algorithm Overview

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