14. Longest Common Prefix

14. Longest Common Prefix/14. Longest Common Prefix.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <OutputType>Exe</OutputType>
+        <TargetFramework>net8.0</TargetFramework>
+        <RootNamespace>_14._Longest_Common_Prefix</RootNamespace>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
+    </PropertyGroup>
+
+</Project>

14. Longest Common Prefix/Program.cs

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+// See https://aka.ms/new-console-template for more information
+
+using _14._Longest_Common_Prefix;
+
+string[] strs = ["flower", "flow", "flight"];
+Console.WriteLine(new Solution().LongestCommonPrefix(strs));

14. Longest Common Prefix/Solution.cs

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+using System.Text;
+
+namespace _14._Longest_Common_Prefix;
+
+public class Solution
+{
+    public string LongestCommonPrefix(string[] strs)
+    {
+        if (strs.Length == 1)
+            return strs[0];
+        StringBuilder sb = new StringBuilder(256);
+        int maxLen = strs.Select(s => s.Length).Min();
+        for (int i = 0; i < maxLen; i++)
+        {
+            char letter;
+            if ((letter = strs[0][i]) != strs[1][i])
+                break;
+            for (int j = 2; j < strs.Length; j++)
+            {
+                if (letter != strs[j][i])
+                {
+                    maxLen = -1;
+                    break;
+                }
+            }
+            if(maxLen != -1)
+                sb.Append(letter);
+        }
+
+        return sb.ToString();
+    }
+}