dotnet-version:6.0.x

-name:Setup NuGet

uses:NuGet/setup-nuget@v1.0.5

uses:NuGet/setup-nuget@v1.2.0

-name:Restore dependencies

run:dotnet restore

1\. Two Sum

Easy

Given an array of integers`nums` and an integer`target`, return_indices of the two numbers such that they add up to`target`_.

You may assume that each input would have**_exactly_ one solution**, and you may not use the_same_ element twice.

You can return the answer in any order.

**Example 1:**

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

**Output:**[0,1]

**Explanation:** Because nums[0] + nums[1] == 9, we return[0, 1].

**Example 2:**

**Input:** nums =[3,2,4], target = 6

**Output:**[1,2]

**Example 3:**

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

**Output:**[0,1]

**Constraints:**

* <code>2 <= nums.length <= 10⁴</code>

* <code>-10⁹ <= nums[i] <= 10⁹</code>

* <code>-10⁹ <= target <= 10⁹</code>

***Only one valid answer exists.**

**Follow-up:** Can you come up with an algorithm that is less than <code>O(n²)</code> time complexity?

[](https://github.com/LeetCode-in-Net/LeetCode-in-Net/blob/main/LICENSE)

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C#-based LeetCode algorithm problem solutions, regularly updated.