[BOJ] 1920 수 찾기

https://www.acmicpc.net/problem/1920

1920번: 수 찾기

이분탐색

using System;
using System.IO;

namespace Assignment01
{
    class Program
    {
        private static int[] arr;
        static StreamReader sr = new StreamReader(Console.OpenStandardInput());
        static StreamWriter sw = new StreamWriter(Console.OpenStandardOutput());

        
        static void Main(string[] args)
        {   
            int n = int.Parse(sr.ReadLine());
            arr = Array.ConvertAll(sr.ReadLine().Split(), int.Parse);
            Array.Sort(arr);
            
            int m  = int.Parse(sr.ReadLine());
            var arr2  = Array.ConvertAll(sr.ReadLine().Split(), int.Parse);
            sr.Close();
            
            for (int i = 0; i < m; i++)
                bsearch(arr2[i]);
            
            sw.Close();
            
                
        }

        static void bsearch(int n)
        {
            int start = 0;
            int end = arr.Length-1;
            int mid = 0;

            while (start <= end)
            {
                mid = (start + end) / 2;
                if (arr[mid] == n)
                {
                    sw.WriteLine("1");
                    return;
                }else if (arr[mid] > n)
                {
                    end = mid - 1;
                }
                else
                {
                    start = mid + 1;
                }
            }

            sw.WriteLine("0");

        }
    }
}