[백준] 2493번 : 탑 [C#]

 

 

using System.IO;
using System.Text;
using System.Linq;
using System.Reflection.PortableExecutable;
using System.Security.Cryptography;
 
namespace 연습장
{
    internal class Program
    {
        static void Main(string[] args)
        {
            using var reader = new StreamReader(Console.OpenStandardInput());
            using var print = new StreamWriter(Console.OpenStandardOutput());
 
            _2493_boj boj = new _2493_boj();
 
            boj.boj_2493();
 
        }
    }
    internal class _2493_boj
    {
        public void boj_2493()
        {
            var reader = new StreamReader(Console.OpenStandardInput());
            var print = new StreamWriter(Console.OpenStandardOutput());
            var sb = new StringBuilder();
            Stack tower = new Stack();
            tower.size = int.Parse(reader.ReadLine());
            tower.stack = new string[tower.size];
 
            string[] input = reader.ReadLine().Split();
            string[] result = new string[tower.size];
 
            for (int i = 0; i < tower.size; i++)
            {
                while (tower.top != -1 && int.Parse(input[i]) > int.Parse(input[int.Parse(tower.peek())]))
                {
                    tower.pop();
                }
                sb.Append(tower.top == -1 ? "0" : (int.Parse(tower.peek()) + 1).ToString());
                if (i != tower.size - 1)
                    sb.Append(' ');
                tower.push(i.ToString());
            }
 
            print.Write(sb);
            print.Flush();
 
        }
    }
    public class Stack
    {
        public int top = -1;
        public string[] stack;
        public int size;
 
        public void push(string data)
        {
            stack[++top] = data;
        }
        public string pop()
        {
            string res = null;
            if (top != -1)
            {
                res = stack[top];
                stack[top--] = null;
            }
 
            return res;
        }
        public string peek()
        {
            string res = null;
            if (top != -1)
                res = stack[top];
            return res;
        }
 
    }
}