Three Sum Closest #109

Author: AhmedKhalil777

Algorithms/LeetCode.Algorithms.Tests/LeetCode.Algorithms.Tests.csproj

@@ -4,13 +4,13 @@
     <TargetFramework>net6.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
-
+	<IsTestProject>true</IsTestProject>
     <IsPackable>false</IsPackable>
   </PropertyGroup>
 
   <ItemGroup>
     <PackageReference Include="FluentAssertions" Version="6.7.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.1.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.10.0" />
     <PackageReference Include="xunit" Version="2.4.2" />
     <PackageReference Include="xunit.extensibility.execution" Version="2.4.2" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3">

Algorithms/LeetCode.Algorithms.Tests/T/ThreeSumClosest.Tests.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Text.Json;
+using System.Threading.Tasks;
+
+namespace LeetCode.Algorithms.Tests;
+
+public class ThreeSumClosestClass
+{
+    [Theory]
+    [InlineData("[-1,2,1,-4]", 1,2)]
+    [InlineData("[0,0,0]", 1,0)]
+    public void ThreeSumClosest(string numsArrayJson, int target ,int expected)
+    {
+        var arr = JsonSerializer.Deserialize<int[]>(numsArrayJson);
+        new Algorithms.ThreeSumClosestClass().ThreeSumClosest(arr, target).Should().Be(expected);
+    }
+}

Algorithms/LeetCode.Algorithms/LeetCode.Algorithms/T/ThreeSumClosest.cs

@@ -0,0 +1,48 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace LeetCode.Algorithms;
+
+public class ThreeSumClosestClass
+{
+    public int ThreeSumClosest(int[] nums, int target)
+    {
+        if (nums.Length < 3)
+            return 0;
+
+        Array.Sort(nums);
+        int start = 0;
+        int left = 1;
+        int right = nums.Length - 1;
+        int minDistance = int.MaxValue;
+        int sum = int.MinValue;
+
+        while (start < nums.Length - 2)
+        {
+            while (left < right)
+            {
+                int currSum = nums[start] + nums[left] + nums[right];
+                if (currSum == target)
+                    return target;
+
+                if (currSum < target)
+                    left++;
+                else
+                    right--;
+
+                if (Math.Abs(currSum - target) < minDistance)
+                {
+                    sum = currSum;
+                    minDistance = Math.Abs(currSum - target);
+                }
+            }
+            start++;
+            left = start + 1;
+            right = nums.Length - 1;
+        }
+        return sum;
+    }
+}