LEETCODE-1: Two Sum

CSharpEducation.sln

@@ -2,6 +2,8 @@
 Microsoft Visual Studio Solution File, Format Version 12.00
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 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "LeetCode1", "LeetCode1\LeetCode1.csproj", "{38E465BC-9B06-4120-8060-02C10053AF7D}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -12,5 +14,9 @@ Global
 		{D0083D4D-28D6-438D-A4BD-04917D0FC77F}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{D0083D4D-28D6-438D-A4BD-04917D0FC77F}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{D0083D4D-28D6-438D-A4BD-04917D0FC77F}.Release|Any CPU.Build.0 = Release|Any CPU
+		{38E465BC-9B06-4120-8060-02C10053AF7D}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{38E465BC-9B06-4120-8060-02C10053AF7D}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{38E465BC-9B06-4120-8060-02C10053AF7D}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{38E465BC-9B06-4120-8060-02C10053AF7D}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 EndGlobal

LeetCode1/LeetCode1.csproj

@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <OutputType>Exe</OutputType>
+        <TargetFramework>net8.0</TargetFramework>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
+    </PropertyGroup>
+
+</Project>

LeetCode1/Program.cs

@@ -0,0 +1,35 @@
+// https://leetcode.com/problems/two-sum/
+
+using System.Collections;
+
+int[] result = new Solution().TwoSum([1, 1, 7, 1, 1, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1], 11);
+Array.ForEach(result, Console.WriteLine);
+
+public class Solution
+{
+    public int[] TwoSum(int[] nums, int target)
+    {
+        var result = new int[2];
+        var verifiedNumDict = new Dictionary<int, int>(nums.Length);
+
+        for (var index = 0; index < nums.Length; index++)
+        {
+            var value = nums[index];
+
+            var remain = target - value;
+
+            if (verifiedNumDict.ContainsKey(remain))
+            {
+                result[0] = index;
+                result[1] = verifiedNumDict[remain];
+                break;
+            }
+            else
+            {
+                verifiedNumDict.TryAdd(value, index);
+            }
+        }
+
+        return result;
+    }
+}