using System; using System.Collections.Generic; namespace GradeBook { public class Book { private List grades; public string Name; public Book(string name) { Name = name; grades = new List(); } public void AddGrade(double grade) { this.grades.Add(grade); } public void AddLetterGrade(char letter) { switch (letter) { case 'A': AddGrade(90); break; case 'B': AddGrade(80); break; case 'C': AddGrade(70); break; default: AddGrade(0); break; } } public Statistics GetStatistics() { var result = new Statistics(); result.Average = 0.0; result.highGrade = double.MinValue; result.lowGrade = double.MaxValue; foreach (var grade in this.grades) { result.lowGrade = Math.Min(grade, result.lowGrade); result.highGrade = Math.Max(grade, result.highGrade); result.Average += grade; } // var index = 0; // do // { // result.lowGrade = Math.Min(grades[index], result.lowGrade); // result.highGrade = Math.Max(grades[index], result.highGrade); // result.Average += grades[index]; // index += 1; // } while (index < grades.Count); result.Average /= grades.Count; return result; } } }