C＃中的简单Windows应用程序混乱

Question

My program is messed up bad, and I need help! I already tried c++, and c# is new for me. Experts here at the university said that c# is like c++, and so I tried to widen my perspective on other programming languages other that c++. I tried to make a program that computes the sum of the lowest 3 numbers in 5 inputted numbers on windows application.

to view the design of the windows application is here: Design View

and my messed up code:

namespace Array_excercise
{
   public partial class Form1 : Form
   {
    public Form1()
    {
        InitializeComponent();
    }
    int[] nums = { 0, 0, 0, 0, 0 };
    int[] lownum = { 0, 0, 0,0,0 };
    int[] highnum = { 0, 0, 0, 0, 0 };
    private void computbtn_Click(object sender, EventArgs e)
    {
        nums[0] = Int32.Parse(textBox1.Text);
        nums[1] = Int32.Parse(textBox2.Text);
        nums[2] = Int32.Parse(textBox3.Text);
        nums[3] = Int32.Parse(textBox4.Text);
        nums[4] = Int32.Parse(textBox5.Text);
        int result;
        for (int a = 0; a <= 4; a++)
        {
            if (nums[a] < nums[0])
                lownum[a] = nums[a];
            else if (nums[a] < nums[1])
                lownum[a] = nums[a];
            else if (nums[a] < nums[2])
                lownum[a] = nums[a];
            else if (nums[a] < nums[3])
                lownum[a] = nums[a];
            else if (nums[a] < nums[4])
                lownum[a] = nums[a];
            else
                highnum[a] = nums[a];
        }
    }
}

After that, I don't know how to compute the sum. for now, I'm particularly learning how to use arrays with if and for loop functions. I'll be very grateful if those functions are used in this program.

I thank you in advance!

Answer 1

使用LINQ

var lowSum = nums.OrderBy(n => n).Take(3).Sum();

Answer 2

A one-dimensional array can be sorted with the static Sort() method.

https://msdn.microsoft.com/en-us/library/system.array.sort(v=vs.110).aspx

So in your example, it would go something like:

// populate the array
nums[0] = Int32.Parse(textBox1.Text);
nums[1] = Int32.Parse(textBox2.Text);
nums[2] = Int32.Parse(textBox3.Text);
nums[3] = Int32.Parse(textBox4.Text);
nums[4] = Int32.Parse(textBox5.Text);

// sort the array from lowest to highest
Array.Sort(nums);

// declare a variable to hold the sum
int sum = 0;

// iterate over the first (smallest) three
for(int i=0;i<3; i++)
{
   sum += nums[i];
}

Console.WriteLine("The sum of the three smallest is: " + sum);

Answer 3

Try with some sorting algorithms, for example bubble sort to sort your array:

int c = -1;
for (int i = array.Length; i > 1; i--)
{
    for (int j = 0; j < i - 1; j++)
    {
        c = j;   
        if (array[j] < array[j + 1])
        {
            int temp = array[j];
            array[j] = array[j + 1];
            array[j + 1] = temp;
        }
    }   
}

After you have the sorted array, you can get the sum of the first 3 lowest number:

int sum = 0;
for(int i=0; i < 3; i++)
{
    sum += array[i];
}

Answer 4

After putting all the values into "nums". You can set the values of the two arrays using the following code.

List<int> tempnums = nums.ToList(); //Creates a List from "nums" array.

tempnums.Sort(); //Sorts the List from smallest number to highest

int[] lownums = tempnums.ToArray(); //Creates an array from "tempnums" List.

tempnums.Reverse();//Reverses the values of "tempnums" so that the numbers are highest to lowest.

int[] highnums = tempnums.ToArray();//Creates an array from "tempnums" List.

And then there are two ways to get the result.

int result = 0;
for(int i = 1; i <= 3; i++)
{
    result += nums[i];
}

Or

int result = nums[0]+nums[1]+nums[2];