[BOJ] 1254 팰린드롬 만들기

https://www.acmicpc.net/problem/1254

1254번: 팰린드롬 만들기

 

힌트 

이미 팰린드롬일경우 

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;

namespace _1159
{
    class Program
    {
        static void Main()
        {
            
            StreamReader sr = new StreamReader(Console.OpenStandardInput());
            //StringBuilder sb = new StringBuilder();
            StreamWriter sw = new StreamWriter(Console.OpenStandardOutput());

            //abab
            //a bab a
            //ab ab ba
            //aba b aba
            //abab baba
            
            var str = sr.ReadLine();
            var len = str.Length;
            var list = new List<string>();
            
            //이미 팰린드롬 
            if (str == new string(str.Reverse().ToArray()))
            {
                sw.WriteLine(len);
            }
            else
            {
                for (int i = 0; i < len; i ++)
                {
                    var first = str.Substring(0, i + 1);
                    // sw.Write("{0}\t", first);

                    var mid = "";
                    if (len - (i + 1) > 0)
                    { 
                        mid = str.Substring(i + 1, len - (i + 1));
                        // sw.Write("{0}\t", mid);
                    }
                    // else 
                    //     sw.Write("\t");

                    var last = new string(first.Reverse().ToArray());
                    // sw.WriteLine("{0}", last);

                    if (mid != "" && mid == new string(mid.Reverse().ToArray()))
                    {
                        list.Add(string.Format("{0}{1}{2}", first, mid, last));
                    }
                    //sw.WriteLine(len - (i + 1));
                }

                // foreach (var ele in list)
                // {
                //     sw.WriteLine("--->{0}" , ele);
                // }

                //https://learn.microsoft.com/en-us/dotnet/api/system.collections.generic.list-1.sort?view=net-7.0
                list.Sort((x, y) => x.Length.CompareTo(y.Length));

                // sw.WriteLine(list[0]);
                sw.WriteLine(list[0].Length);
            }

            sr.Close();
            sw.Close();
            
            
            
        }
    }
    
}