顯示兩個數組之間共同和不常見元素的總數？

Question

我有兩個數組：數組testAnswer包含「考試答案」，數組inputAnswers包含「學生對考試的答案」。

當我運行我的代碼時，它顯示了兩個數組（正確答案）和非常規元素（不正確答案）的所有常見元素。但是，我不想實際顯示正確/錯誤的答案，而是希望能夠顯示正確/錯誤答案的總數。

我迄今爲止代碼：

private void button1_Click(object sender, EventArgs e) 
{ 
    //Array holding answers to test 
    string[] testAnswer = new string[20] { "B", "D", "A", "A", "C", "A", "B", "A", "C", "D", "B", "C", "D", "A", "D", "C", "C", "B", "D", "A" }; 
    string a = String.Join(", ", testAnswer); 

    //Reads text file line by line. Stores in array, each line of the file is an element in the array 
    string[] inputAnswer = System.IO.File.ReadAllLines(@"C:\Users\Momo\Desktop\UNI\Software tech\test.txt"); 

    string b = String.Join(", ", inputAnswer); 

    //Increments through array elements in both arrays and checks for matching elements. Displays in listBox. 
    for (int i = 0; i < testAnswer.Length; i++) 
    { 
     if (testAnswer[i] == inputAnswer[i]) 
      listBox1.Items.Add(inputAnswer[i]); // or testAnswer[i], as appropriate 
    } 

    //Increments through array elements in both arrays and checks for uncommon elements. Displays in listBox. 
    for (int i = 0; i < testAnswer.Length; i++) 
    { 
     if (testAnswer[i] != inputAnswer[i]) 
      listBox2.Items.Add(inputAnswer[i]); 
    } 
} 

Answer 1

下面的代碼將提供這將按住接聽結束2個整數：

private void button1_Click(object sender, EventArgs e) 
{ 
    string[] testAnswer = new string[20] { "B", "D", "A", "A", "C", "A", "B", "A", "C", "D", "B", "C", "D", "A", "D", "C", "C", "B", "D", "A" }; 
    string a = String.Join(", ", testAnswer); 



    //Reads text file line by line. Stores in array, each line of the file is an element in the array 
    string[] inputAnswer = System.IO.File.ReadAllLines(@"C:\Users\Momo\Desktop\UNI\Software tech\test.txt"); 

    string b = String.Join(", ", inputAnswer); 


    //Increments through array elements in both arrays and checks for matching elements. 
    //Displays in listBox. 
    for (int i = 0; i < testAnswer.Length; i++) 
    { 
     if (testAnswer[i] == inputAnswer[i]) 
      listBox1.Items.Add(inputAnswer[i]); // or testAnswer[i], as appropriate 
     else 
      listBox2.Items.Add(inputAnswer[i]); 
     } 

    int correctAns = listbox1.Items.Count; 
    int wringAns = listbox2.Items.Count; 
} 

Answer 2

常見的答案計數將在Enumerable.Intersect結果項目數，罕見 - Enumerable.Except結果項目數。

更新：只要有人在評論中提到，它會產生錯誤的答案，證明它不會：

var testAnswers = new[] { 1, 2, 3 }; 
    var inputAnswers = new[] { 3, 2, 1 }; 
    var commonAnswers = testAnswers 
      .Select((x, index) => Tuple.Create(x, index)) 
      .Intersect(inputAnswers.Select((y, index) => Tuple.Create(y, index)));  

Answer 3

下面介紹如何使用LINQ to得到結果：

var results = 
    testAnswer 
     .Zip(inputAnswer, (t, i) => new { t, i }) 
     .Aggregate(new { Correct = 0, Incorrect = 0 }, 
      (a, ti) => new 
      { 
       Correct = a.Correct + (ti.t == ti.i ? 1 : 0), 
       Incorrect = a.Incorrect + (ti.t != ti.i ? 1 : 0) 
      }); 

它會產生用這種結果的一個匿名變量：

另一種方法是：

var query = 
    testAnswer 
     .Zip(inputAnswer, (t, i) => t == i) 
     .ToLookup(x => x); 

var results = new 
{ 
    Correct = query[true].Count(), 
    Incorrect = query[false].Count() 
};