Windows programming (c-sharp) assignment 1

Assignment1_1.cs

/**
* Windows programming (c#) assignment 1.1
* https://repl.it/@Gumball12/Windows-programming-c-sharp-assignment-11
*
* @author HaeJun Seo
* @since Mar 14, 2019
*/

using System;

class Program {
  public static void Main (string[] args) {
    /* variables */

    // declare string variable
    string name;

    // define 1d array(string)
    string[] names = { "발리", "둘리", "몰리", "물리", "살리" };

    // user input
    Console.Write("찾고자 하는 이름을 입력해주세요: ");
    name = Console.ReadLine();

    // foreaching
    foreach (string n in names) { // n: an array element ('names' array)
      if (n == name) {
        Console.WriteLine($"\n 일치하는 단어를 찾았습니다: {n}");
        break; // break foreach
      }
    }

    // exit interrupt
    Console.Write("종료하려면 엔터 키를 눌러주십시오...");
    Console.ReadLine();
  }
}

Assignment1_2.cs

/**
* Windows programming (c#) assignment 1.2
* https://repl.it/@Gumball12/Windows-programming-c-sharp-assignment-12
*
* @author HaeJun Seo
* @since Mar 13, 2019
*/

using System; // Convert, Func, Math, ...
using System.Linq; // Enumerable
using System.Collections.Generic; // List

class Program {
  public static void Main (string[] args) {
    /* tools (using c# lambda expression) */

    Func<string, string> trim = s => s.Trim();
    Func<string, string[]> splitRest = s => s.Split(',');
    Func<string[], string[]> trimMap = sa => sa.Select(trim).ToArray();
    Func<double, int, double> computeDecimal = (target, d) => Math.Floor(target * 10 * d) / (10.0 * d);

    Func<string[], int> summation = sa => sa.Aggregate(0, (acc, s) => acc + Convert.ToInt32(s));
    Func<string[], double> mean = sa => summation(sa) / Convert.ToDouble(sa.OfType<string>().ToList().Count);

    Func<int, int, int> intCompare = (a, b) => a.CompareTo(b);

    // quicksort
    Func<List<List<string>>, List<List<string>>> qs = null;

    Func<List<List<string>>, int, int, List<List<string>>> swap = (list, a, b) => {
      // swap list elements
      List<string> tmp = new List<string>(list[a]);
      list[a] = list[b];
      list[b] = tmp;

      return list;
    };

    /* variables */

    int studentCnt;

    /* getting user input */

    Console.Write("Insert number of student: ");

    // 학생의 수를 입력받음
    studentCnt = Convert.ToInt32(Console.ReadLine());

    // 2차원 배열 선언
    List<List<string>> scores = new List<List<string>>();

    /* compute scores */

    Console.WriteLine("Insert score (이름/국어/영어/수학):");

    // 성적을 입력받고 배열에 저장
    // 학생의 이름, 총점, 평균 계산
    for (int ind = 0; ind < studentCnt; ind++) {
      scores.Add(new List<string>( // add element
        // getting user input
        trimMap(splitRest(Console.ReadLine()))
      ));

      // compute a total score (index: 4)
      scores[ind].Add(
        Convert.ToString(summation(scores[ind].GetRange(1, 3).ToArray()))
      );

      // compute a mean score (index: 5)
      scores[ind].Add(
        Convert.ToString(
          computeDecimal(mean(scores[ind].GetRange(1, 3).ToArray()), 1)
        )
      );
    }

    /**
    * compute 'rank' using QUICKSORT
    * reference: https://en.wikipedia.org/wiki/Quicksort
    */
    // 학생의 석차 계산

    qs = (ul) => { // ul: Unsorted List
      int pivot = 0;
      int j = 0, i = 1;

      while (i <= ul.Count - 1) { // iterate ul
        int comp = intCompare( // comparing 
          Convert.ToInt32(ul[pivot][4]),
          Convert.ToInt32(ul[i][4])
        );

        if (comp == 1) { // greater than
          swap(ul, ++j, i); // swapping of two elements (j + 1, i)
        }

        i++; // next element
      }

      // swapping of two elements (pivot, j)
      swap(ul, pivot, j);
      pivot = j;

      // recursion
      if (ul.Count - 1 > 1) {
        List<List<string>> slice = null;

        if (0 < pivot) {
          slice = ul.GetRange(0, pivot);
          ul.RemoveRange(0, pivot);
          ul.InsertRange(0, qs(slice));
        }

        if (pivot < ul.Count - 1) {
          slice = ul.GetRange(pivot + 1, ul.Count - pivot - 1);
          ul.RemoveRange(pivot + 1, ul.Count - pivot - 1);
          ul.InsertRange(pivot + 1, qs(slice));
        }
      }

      return ul;
    };

    // sorting
    qs(scores).Reverse();

    /* print */
    // 학생의 이름, 국어, 영어, 수학, 총점, 평균, 석차 출력

    int rank = 1;

    Console.WriteLine("\n\n\n======= 결 과 =======\n");

    scores.ForEach(score => Console.WriteLine($"이름: {score[0]}, 국어: {score[1]}, 영어: {score[2]}, 수학: {score[3]}, 총점: {score[4]}, 평균: {score[5]}, 석차: {rank++}"));

    // exit interrupt
    Console.Write("\n종료하려면 엔터 키를 눌러주십시오...");
    Console.ReadLine();
  }
}