如何排除数组的值？

Question

How do you create a method that excludes the lowest temperature and calculate the average temp. i just want a hint and not the complete solution, as I want to solve my programming problems myself. I have had only about 10 classes.. to comment on people comments my professor does not lecture and i have read my book looked back through it multiple times.

I made this program to take a number from a user. That number is added into the array. That array is used to create an instance of the class Temp to print the lowest and highest temps.

class Program
{
    static void Main(string[] args)
    {
        Console.Write("Enter a Temperature in Degrees:");
        string n = Console.ReadLine();
        int number = Convert.ToInt32( n); 
        Temp t = new Temp(100, 52, 98, 30, 11, 54, number);
        Console.WriteLine("Lowest Temperature:{0}", t.lowest());
        Console.WriteLine("Highest Temperature: {0}", t.highest());
        Console.WriteLine("Average Temperature: {0}", t.Average());
    }

    public class Temp
    {
        private int[] temp = new int[7]; // array 
        public Temp(int d1, int d2, int d3, int d4, int d5, int d6, int d7) // constructor with 7 parameters
        {
            temp[0] = d1; // assigning constructor parameters to array
            temp[1] = d2;
            temp[2] = d3;
            temp[3] = d4;
            temp[4] = d5;
            temp[5] = d6;
            temp[6] = d7;
        }

        public int lowest() // returning the lowest value of the set of numbers
        {
            int smallest = 150;
            for (int c = 0; c < 7; c++)
            {
                if (temp[c] < smallest)
                {
                    smallest = temp[c];
                }

            }
            return smallest;
        }

        public int highest()
        {
            int highest = -1;
            for (int c = 0; c < 7; c++)
            {
                if (temp[c] > highest)
                {
                    highest = temp[c];
                }
            }

            return highest;
        }

        public double Average()
        {
            double average = 0;
            for (int c = 0; c < 7; c++)
            {

            }
            return average;
        }
    }
}

Answer 1

This is very easy to do with a single loop:

public double Average()
{
    // Initialize smallest with the first value.
    // The loop will find the *real* smallest value.
    int smallest = temp[0];

    // To calculate the average, we need to find the sum of all our temperatures,
    // except the smallest.
    int sum = temp[0];

    // The loop does two things:
    // 1. Adds all of the values.
    // 2. Determines the smallest value.
    for (int c = 1; c < temp.Length; ++c)
    {
        if (temp[c] < smallest)
        {
            smallest = temp[c];    
        }
        sum += temp[c];
    }
    // The computed sum includes all of the values.
    // Subtract the smallest.
    sum -= smallest;

    double avg = 0;
    // and divide by (Length - 1)
    // The check here makes sure that we don't divide by 0!
    if (temp.Length > 1)
    {
        avg = (double)sum/(temp.Length-1);
    }
   return avg;
}

Answer 2

Here is a little bit different version than Douglas posted (of course his version is totally fine and well described, I just put it for your review). It doesn't use lowest() method call.

public double Average()
{
    double sum = temp[0]; // sum of temperatures, starting from value of first one in array
    double lowest = temp[0]; // buffer for lowest temperature value
    for (int c = 1; c < 7; c++) // start loop from second position in array
    {
        if (temp[c] < lowest) // checking if next value in array is smaller than the lowest one so far...
        {
            lowest = temp[c]; // ...if so, value of variable lowest is changing
        }
        sum = sum + temp[c]; // adding temparatures value to variable sum, one by one
    }
    sum = sum - lowest; // at the end we substract lowest value from sum of all temperatures
    double average = sum / 6; // average value calculation
    return average;
}

EDIT: Jim Mischel was first ;-) . His version is also more flexible thanks to using temp.Length, not static number (7 in this case).

Answer 3

You need to add error handling but this can help give you a start

var ints = new List<int>();
var newInts = ints.OrderBy(x => x).ToList();
newInts.RemoveAt(0);
var avg = newInts.Average();

Answer 4

You can do this easily with a few LINQ functions. There are plenty of other ways to do this but they will all be similar. If there is more than one min value your average will not include any of them.

int min = myArray.Min(); // get the min element
var withoutMin = myArray.Where(x => x != min); // get a new list without the min element
double mean = withoutMin.Average(); // take the sum and divide it by the count 

Answer 5

    public double Average()
    {
         var tempsToUse = temp.OrderByDescending(t => t).Take(temp.Length - 1);

         return tempsToUse.Average();
    }

Edited to include full function signature.