Programers_Level_0.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Algorithm
{
    public class A_1_1_OddEven
    {
        public string solution(int num)
        {
            if (num % 2 == 0) return "Even";
            else return "Odd";
        }
    }
    public class A_1_2_Average
    {
        public double solution(int[] arr)
        {
            if (arr.Length == 0) { return 0; }

            double average = 0;
            foreach (int i in arr)
            {
                average += (double)i;
            }
            if (average == 0) return average;
            else return average / arr.Length;
        }
    }
    public class A_1_3_ciphers
    {
        public int solution(int n)
        {
            int answer = 0;
            while (n > 0)
            {
                answer += n % 10;
                n /= 10;
            }
            return answer;
        }
    }
    public class A_1_4_aliquot
    {
        public int solution(int n)
        {
            if (n > 0)
            {
                int sum = 0;
                for (int i = 1; i <= n; i++)
                {
                    if (n % i == 0) sum += i;
                }
                return sum;
            }

            return 0;
        }
    }
    public class A_1_5_remainder1
    {
        public int solution(int n)
        {
            for (int i = 2; i < n; i++)
            {
                if (n % i == 1) return i;
            }

            return -1;
        }
    }
    public class A_1_6_termx
    {
        public long[] solution(int x, int n)
        {
            long[] answer = new long[n];
            for (int i = 0; i < n; i++)
            {
                answer[i] = (long)x * (i + 1);
            }
            return answer;
        }
    }
    public class A_1_7_naturalnumberarray
    {
        public int[] solution(long n)
        {
            string number = n.ToString();
            int[] answer = new int[number.Length];

            for (int i = 0; i < number.Length; i++)
            {
                answer[i] = (int)(n % 10);
                n /= 10;
            }

            return answer;
        }
    }
    public class A_1_8_parseint
    {
        public int solution(string s)
        {
            return int.Parse(s);
        }
    }
    public class A_1_9_squareroot
    {
        public static long solution(long n)
        {
            for (long answer = 1; answer * answer <= n; answer++)
            {
                if (answer * answer == n) return (long)((answer + 1) * (answer + 1));
            }
            return (long)-1;
        }
    }
    public class A_1_10_descendingorder
    {
        public static long solution(long n)
        {

            int[] ints = new int[n.ToString().Length];
            for (int i = 0; i < ints.Length; i++) { ints[i] = (int)(n % 10); n /= 10; }

            Array.Sort(ints);
            Array.Reverse(ints);

            string s = "";
            for (int i = 0; i < ints.Length; i++) { s += ints[i].ToString(); Console.Write(ints[i]); }

            return long.Parse(s);

        }
    }
    public class A_1_11_harshadnumber
    {
        public static bool solution(int x)
        {
            int _x = x;
            int sum = 0;

            for (int i = 0; i < _x.ToString().Length; i++)
            {
                sum += x % 10;
                x /= 10;
            }

            if (_x % sum == 0) return true;
            return false;


        }
    }
    public class A_1_12_intsum
    {
        public static long solution(int a, int b)
        {
            long answer = a;
            while (a != b)
            {
                a = a > b ? a - 1 : a + 1;
                answer += a;
            }
            return answer;
        }
    }
    public class A_1_13_Collatz
    {
        public static int solution(int num)
        {
            for (int i = 0; i < 500; i++)
            {
                if (num == 1) return i;
                num = (num % 2 == 0) ? num / 2 : num * 3 + 1;
            }

            return -1;
        }
    }
    public class A_1_14_Kim
    {
        public string solution(string[] seoul)
        {
            for (int i = 0; i < seoul.Length; i++)
            {
                if (seoul[i] == "Kim") return "김서방은 " + i.ToString() + "에 있다";
            }

            return "";
        }
    }
    public class A_1_15_divisor
    {
        public static int[] solution(int[] arr, int divisor)
        {
            Array.Sort(arr);
            List<int> list = new List<int>();

            for (int i = 0; i < arr.Length; i++)
            {
                if (arr[i] % divisor == 0)
                {
                    list.Add(arr[i]);
                }
            }

            if (list.Count == 0) return new int[] { -1 };

            return list.ToArray();
        }
    }
    public class A_1_16_YinYang
    {
        public static int solution(int[] absolutes, bool[] signs)
        {
            int answer = 0;
            for (int i = 0; i < absolutes.Length; i++)
            {
                answer = signs[i] ? answer + absolutes[i] : answer - absolutes[i];
            }
            return answer;
        }
    }
    public class A_1_17_phone_number
    {
        public static string solution(string phone_number)
        {
            char[] answer = phone_number.ToCharArray();

            for (int i = 0; i < answer.Length - 4; i++)
            {
                answer[i] = '*';
            }

            return new string(answer);
        }
    }
    public class A_1_18_numbers
    {
        public int solution(int[] numbers)
        {
            int answer = 45;

            for (int i = 0; i < numbers.Length; i++)
            {
                answer -= numbers[i];
            }

            return answer;
        }

        public int solution2(int[] numbers)
        {
            var numberArray = new int[] { 1, 2, 3, 4, 5, 6, 7, 8, 9 };

            return numberArray.Except(numbers).Sum();
        }
    }
    public class A_1_19_Remove_smallest_number
    {
        public static int[] solution(int[] arr)
        {
            if (arr.Length < 2) return new int[] { -1 };
            return arr.Except(new int[] { arr.Min() }).ToArray();
        }
    }
    public class A_1_20_center
    {
        public string solution(string s)
        {
            string answer = "";
            answer = (s.Length % 2 == 0) ? s.Substring(s.Length / 2 - 1, 2) : s.Substring(s.Length / 2, 1);
            return answer;
        }
    }
    public class A_1_21_subak
    {
        public string solution(int n)
        {
            string answer = "";

            for (int i = 0; i < n; i++)
            {
                answer += (i % 2 == 0) ? "수" : "박";
            }

            return answer;
        }
    }
    public class A_1_22_inner_product

    {
        public int solution(int[] a, int[] b)
        {
            int answer = 0;
            for (int i = 0; i < a.Length; i++)
            {
                answer += a[i] * b[i];
            }
            return answer;
        }
    }
    public class A_1_23_aliquot
    {
        public int solution(int left, int right)
        {
            int answer = 0;
            for (int i = left; i <= right; i++)
            {
                answer = (findaliquotnumber(i) % 2 == 0) ? answer + i : answer - i;
            }
            return answer;
        }

        public int findaliquotnumber(int n)
        {
            int count = 0;
            for (int i = 1; i <= n; i++)
            {
                if (n % i == 0) { count++; }
            }
            return count;
        }
    }
    public class A_1_24_string_descending_order
    {
        public string solution(string s)
        {
            char[] answer = s.ToCharArray();
            Array.Sort(answer);
            Array.Reverse(answer);
            return new string(answer);
        }
    }
    public class A_1_25_less_price
    {
        public long solution(int price, int money, int count)
        {
            long total = 0;
            for (int j = 1; j <= count; j++)
            {
                total += (long)(price * j);

            }

            if (total <= money) return 0;
            return (long)(total - money);
        }
    }
    public class A_1_26_basic_string
    {
        public static bool solution(string s)
        {
            int tmp;

            if (s.Length == 4 || s.Length == 6)
            {
                return int.TryParse(s, out tmp);
            }

            return false;
        }
    }
    public class A_1_27_array_addiction
    {
        public int[,] solution(int[,] arr1, int[,] arr2)
        {
            int[,] answer = new int[arr1.GetLength(0), arr1.GetLength(1)];

            for (int i = 0; i < arr2.GetLength(0); i++)
            {
                for (int j = 0; j < arr2.GetLength(1); j++)
                {
                    answer[i, j] = arr1[i, j] + arr2[i, j];
                }
            }

            return answer;
        }
    }
    public class A_1_28_rectangle_star
    {
        //    String[] s;

        //    Console.Clear();
        //    s = Console.ReadLine().Split(' ');

        //    int a = Int32.Parse(s[0]);
        //    int b = Int32.Parse(s[1]);
        //    for(int i = 0; i<b; i++){
        //        for(int j=0;j<a;j++){
        //            Console.Write("*");
        //        }
        //Console.WriteLine();
    }
    public class A_1_29_greatestDivisor_LeastMultiple
    {
        public static int[] solution(int n, int m)
        {
            int greatestDivisor = 1;

            int ntmp = n;
            int mtmp = m;

            List<int> Divisors = new List<int>();
            int divisor = 2;


            while ((divisor < n / 2 || divisor < m / 2))
            {
                if (ntmp % divisor == 0 && mtmp % divisor == 0)
                {
                    Divisors.Add(divisor);
                    ntmp /= divisor;
                    mtmp /= divisor;
                    divisor = 1;
                }
                divisor++;
            }

            if (Divisors.Count == 0)
            {
                return new int[] { 1, n * m };
            }

            foreach (int i in Divisors)
            {
                greatestDivisor *= i;
            }

            return new int[] { greatestDivisor, greatestDivisor * ntmp * mtmp };
        }
    }
    public class A_1_30_ternary_scale
    {
        public static int solution(int n)
        {
            int answer = 0;
            while (n > 0)
            {
                answer *= 3;
                answer += n % 3;
                n /= 3;
            }
            return answer;
        }
    }

}