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How to Display a Jagged Array? - C#

I am trying to get a jagged array that will solve the sums of the elements from dailyTemperature and that will successfully display them in the Main () under the Weather class. This is what I have so far.
public int[,] GetTemperatures()
{
int[,] dailyTemperature =
{
{38, 40, 42, 34},
{55, 41, 40, 30},
{28, 39, 21, 60},
{61, 52, 43, 42},
{35, 36, 30, 29},
{24, 33, 37, 40}
};
Console.Write(" ");
for (int i = 0; i < dailyTemperature.Length; i++)
{
Console.Write(dailyTemperature[i] + " ");
}
Console.WriteLine();
for (int i = 0; i < dailyTemperature.GetLength(0); i++)
{
Console.Write(dailyTemperature[i].Substring(0, dailyTemperature[i].Length - 1) + " ");
for (int j = 0; j < dailyTemperature.GetLength(1); j++)
{
Console.Write(dailyTemperature[i, j] + " ");
}
Console.WriteLine();
}
return dailyTemperature;
}
{
public int[] GetTemperatureSum(int [,] dailyTemperature)
{
int[][] temperatureSum= new int[6][];
temperatureSum[0][1] = dailyTemperature[0, 0] + dailyTemperature[0, 1] + dailyTemperature[0, 2] + dailyTemperature[0, 3];
temperatureSum[0][2] = dailyTemperature[1, 0] + dailyTemperature[1, 1] + dailyTemperature[1, 2] + dailyTemperature[1, 3];
temperatureSum[0][3] = dailyTemperature[2, 0] + dailyTemperature[2, 1] + dailyTemperature[2, 2] + dailyTemperature[2, 3];
temperatureSum[0][4] = dailyTemperature[3, 0] + dailyTemperature[3, 1] + dailyTemperature[3, 2] + dailyTemperature[3, 3];
temperatureSum[0][5] = dailyTemperature[4, 0] + dailyTemperature[4, 1] + dailyTemperature[4, 2] + dailyTemperature[4, 3];
temperatureSum[0][6] = dailyTemperature[5, 0] +dailyTemperature[5, 1] + dailyTemperature[5, 2] + dailyTemperature[5, 3];
for (int i = 0; i < temperatureSum.GetLength(0); i++)
{
for (int j=0; j<temperatureSum.GetLength(1); j++)
{
Console.Write(temperatureSum[i][j]);
}
Console.WriteLine();
}
return temperatureSum;
}
static void Main(string[] args)
{
Weather weather= new Weather();
{
weather.GetTemperatures();
weather.GetTemperatureSum(dailyTemperature);
}
};
My strategy here is to display all of these methods through the Main() method, however I am getting an error under (dailyTemperature) by weather.GetTemperatureSum. This is what the error says, "An object reference is required for the nonstatic field, method, or property 'member'".
I'd love it if someone could help me on this, although as I understand the formatting has to be relatively similar to this. I absolutely need to, for example, solve the sums through the computer as opposed to doing so manually. Thanks.

More details about:
Multidimensional Arrays
Jagged Arrays
Multidimensional Array [][] vs [,] [duplicate]
int[,] dailyTemperatures =
{
{ 38, 40, 42, 34 },
{ 55, 41, 40, 30 },
{ 28, 39, 21, 60 },
{ 61, 52, 43, 42 },
{ 35, 36, 30, 29 },
{ 24, 33, 37, 40 }
};
Weather.GetTemperatures(dailyTemperatures);
Weather.GetTemperatureSum(dailyTemperatures);
public static class Weather
{
public static int[,] GetTemperatures(int[,] dailyTemperatures)
{
var rows = dailyTemperatures.GetUpperBound(0) + 1;
var columns = dailyTemperatures.Length / rows;
for (var i = 0; i < rows; i++)
{
for (var j = 0; j < columns; j++)
{
Console.Write($"{dailyTemperatures[i, j]} \t");
}
Console.WriteLine();
}
return dailyTemperatures;
}
public static int[] GetTemperatureSum(int[,] dailyTemperature)
{
var temperatureSum = new int[6];
temperatureSum[0] = dailyTemperature[0, 0] + dailyTemperature[0, 1] + dailyTemperature[0, 2] + dailyTemperature[0, 3];
temperatureSum[1] = dailyTemperature[1, 0] + dailyTemperature[1, 1] + dailyTemperature[1, 2] + dailyTemperature[1, 3];
temperatureSum[2] = dailyTemperature[2, 0] + dailyTemperature[2, 1] + dailyTemperature[2, 2] + dailyTemperature[2, 3];
temperatureSum[3] = dailyTemperature[3, 0] + dailyTemperature[3, 1] + dailyTemperature[3, 2] + dailyTemperature[3, 3];
temperatureSum[4] = dailyTemperature[4, 0] + dailyTemperature[4, 1] + dailyTemperature[4, 2] + dailyTemperature[4, 3];
temperatureSum[5] = dailyTemperature[5, 0] + dailyTemperature[5, 1] + dailyTemperature[5, 2] + dailyTemperature[5, 3];
for (var i = 0; i < temperatureSum.GetLength(0); i++)
{
Console.WriteLine(temperatureSum[i]);
}
return temperatureSum;
}
}
In the GetTemperatureSum method, the returned type is an array (int[]).
It is better to pass dailyTemperatures variable as a method parameter

C#. Min path from left top corner to right bottom on ( n x n ) table

Im having trouble with code, I get
System.IndexOutOfRangeException
in the first loop in the find() method. Could you guys help me? I cant figure out whats wrong.
I've found this code for java and changed a little bit for C#. In java code there was int[][] A, Ive changed it to int[,]. P.S on java, code works.
class Program
{
static void Main(string[] args)
{
int[,] A = { { 1, 7, 9, 2 }, { 8, 6, 3, 2 }, { 1, 6, 7, 8 },
{ 2, 9, 8, 2 } };
Console.WriteLine("{0}", find(A));
}
public static int find(int[,] A)
{
int[,] solution = new int[A.Length + 1, A.Length + 1];
solution[0, 0] = A[0, 0];
for(int i = 1; i < A.Length; i++)
{
solution[0, i] = A[0, i] + solution[0, i - 1]; //IndexOutOfRangeException
}
for(int i = 1; i < A.Length; i++)
{
solution[i, 0] = A[i, 0] + solution[i - 1, 0];
}
for(int i = 1; i < A.Length; i++)
{
for(int j = 1; j < A.Length; j++)
{
solution[i, j] = A[i, j]
+ Math.Min(solution[i - 1, j], solution[i, j - 1]);
}
}
return solution[A.Length - 1, A.Length - 1];
}
}

The problem is that in a jagged array ([,]) the property Length will give you the overall amount of elements, in your case A.Length == 16 but you want only one dimension. The solution would be to use GetLength.
for (int i = 1; i < A.GetLength(1); i++)
you need to use 0 for the X-Dimension and 1 for the Y-Dimenstion ( [X,Y]) see the documenation for details.
This is how your method should look like:
public static int find(int[,] A)
{
int[,] solution = new int[A.GetLength(0) + 1, A.GetLength(1)+ 1];
solution[0, 0] = A[0, 0];
for (int i = 1; i < A.GetLength(1); i++)
{
solution[0, i] = A[0, i] + solution[0, i - 1];
}
for (int i = 1; i < A.GetLength(0); i++)
{
solution[i, 0] = A[i, 0] + solution[i - 1, 0];
}
for (int i = 1; i < A.GetLength(0); i++)
{
for (int j = 1; j < A.GetLength(1); j++)
{
solution[i, j] = A[i, j]
+ Math.Min(solution[i - 1, j], solution[i, j - 1]);
}
}
return solution[A.GetLength(0) - 1, A.GetLength(1) - 1];
}

Average Array for int values in a 2D String Array

I am having a bit of trouble with my program which holds student names and grades in a 2D string array. Basically, I have a second (1D) array that will hold average grade for each student.
code so far:
class Program
{
static void Main(string[] args)
{
// Create a 2D array for names, and their grades, and an array for average grades
string[,] studentGrades = new string[5, 8];
int[] average = new int[studentGrades.GetLength(0)];
// Set student names/grades manually
studentGrades[0, 0] = "Steve";
studentGrades[0, 1] = "69";
studentGrades[0, 2] = "80";
studentGrades[0, 3] = "66";
studentGrades[0, 4] = "75";
studentGrades[0, 5] = "90";
studentGrades[0, 6] = "69";
studentGrades[0, 7] = "98";
studentGrades[1, 0] = "Bob";
studentGrades[1, 1] = "73";
studentGrades[1, 2] = "67";
studentGrades[1, 3] = "65";
studentGrades[1, 4] = "91";
studentGrades[1, 5] = "48";
studentGrades[1, 6] = "33";
studentGrades[1, 7] = "94";
studentGrades[2, 0] = "Lewis";
studentGrades[2, 1] = "67";
studentGrades[2, 2] = "80";
studentGrades[2, 3] = "66";
studentGrades[2, 4] = "75";
studentGrades[2, 5] = "90";
studentGrades[2, 6] = "69";
studentGrades[2, 7] = "63";
studentGrades[3, 0] = "Sara";
studentGrades[3, 1] = "55";
studentGrades[3, 2] = "58";
studentGrades[3, 3] = "63";
studentGrades[3, 4] = "70";
studentGrades[3, 5] = "55";
studentGrades[3, 6] = "55";
studentGrades[3, 7] = "76";
studentGrades[4, 0] = "Xavier";
studentGrades[4, 1] = "22";
studentGrades[4, 2] = "27";
studentGrades[4, 3] = "25";
studentGrades[4, 4] = "19";
studentGrades[4, 5] = "42";
studentGrades[4, 6] = "18";
studentGrades[4, 7] = "32";
// Loop the array dimensions and output/format output the names/grades
for (int name = 0; name < studentGrades.GetLength(0); name++)
{
for (int grade = 0; grade < studentGrades.GetLength(1); grade++)
{
Console.WriteLine(studentGrades[name, grade]);
}
Console.WriteLine("");
}
for (int i = 0; i < studentGrades.GetLength(0); i++)
{
for (int j = 0; j < studentGrades.GetLength(1); j++)
{
average[j] += int.Parse(studentGrades[i, j]);
}
}
}
}
I get an un-handled exception in regards to the input string not being in the correct format where the average is set.
All help is appreciated!
Update
I've reviewed the solutions of code so far below, and I'm still having issues with getting the grade average to work as intended. I have 5 students with 7 grades. I want the program to output the average of each persons grades below their column.
Code:
static void Main(string[] args)
{
// Create a 2D array for names, and their grades, and an array for average grades
string[,] studentGrades = new string[5, 8];
int[] average = new int[studentGrades.GetLength(1)];
// Set student names/grades manually
//As done above, excluded for brevity reasons
// Loop the array dimensions and output/format output the names/grades
for (int grade = 0; grade < studentGrades.GetLength(1); grade++)
{
for (int name = 0; name < studentGrades.GetLength(0); name++)
{
// Composite formatting is used to align names/grades in grid -- specifically the alignment component.
// Making the value higher (more neg) will increase spacing between elements
// Positive number would right align elements instead
Console.Write("{0, -15}", studentGrades[name, grade]);
}
// Moves each printed grade to a new line
Console.WriteLine("");
}
for (int i = 0; i < studentGrades.GetLength(0); i++)
{
for (int j = 1; j < studentGrades.GetLength(1); j++)
{
average[j] += int.Parse(studentGrades[i, j]);
}
average[i] /= studentGrades.GetLength(1) - 1;
}
for (int i = 0; i <= average.GetLength(0) - 1; i++)
{
Console.Write("{0, -15}", i);
}
Console.WriteLine("");
}
Update 2
It seems that the average array is not being properly populated. It seems to just print out 1, 2, 3, 4, 5, 6, 7 if I remove the average division. Furthermore, if I change averages' length to 5 -- or the length of the amount of names since there will only be 5 values, it breaks. This is likely because it's trying to add 7 items to a 5 item array.

Every studentGrages[*, 0] element is not integer so you can't parse it to int
Skip the first elements
for (int i = 0; i < studentGrades.GetLength(0); i++)
{
for (int j = 1; j < studentGrades.GetLength(1); j++)
{
average[j] += int.Parse(studentGrades[i, j]);
}
}

You have to change this part of code:
// Store the average as a double array, otherwise you can't have averages with decimal values.
double[] average = new double[studentGrades.GetLength(0)];
for (int i = 0; i < studentGrades.GetLength(0); i++)
{
// Start from j = 1, as j = 0 would get a name instead of a grade.
for (int j = 1; j < studentGrades.GetLength(1); j++)
{
// Here use average[i] instead of average[j], because you want
// the average grade for each student.
average[i] += int.Parse(studentGrades[i, j]);
}
// Finish calculating the average.
// GetLength(0) - 1 because the first item is a name, not a grade.
average[i] /= studentGrades.GetLength(1) - 1;
}
for (int i = 0; i <= average.GetLength(0) - 1; i++)
{
// Show at most 2 decimal digits.
Console.Write("{0, -15:#.##}", average[i]);
}

Your trying to include the string of the names (on the 0 index) with the average. e.g int.Parse("Steve") which is causing the exception, just skip on the first element on each colum.
for (int j = 1; j < studentGrades.GetLength(1); j++)

As other have rightly pointed out, you need to change the 0 to a 1 in the following line:
for (int j = 1; j < studentGrades.GetLength(1); j++)
Otherwise you're going to try to parse the name as an integer.
Also you need to change the index on average inside the loop to i rather than j.
average[i] += int.Parse(studentGrades[i, j]);
The other issue that you're going to have is that you're using integer mathematics - so when you do something like 7 / 2 you get an answer of 3 and not 3.5.
If I were you, and you don't want to change your data structure, I would do it this way:
var results =
studentGrades
.Cast<string>()
.Select((x, n) => new { x, n })
.GroupBy(xn => xn.n / studentGrades.GetLength(1), xn => xn.x)
.Select(xs => new
{
student = xs.First(),
average = xs.Skip(1).Select(x => int.Parse(x)).Average(),
})
.ToArray();
That gives me:
Alternatively, I would suggest that you change your data structure to this:
var studentGrades = new []
{
new { student = "Steve", grades = new [] { 69, 80, 66, 75, 90, 69, 98, } },
new { student = "Bob", grades = new [] { 73, 67, 65, 91, 48, 33, 94, } },
new { student = "Lewis", grades = new [] { 67, 80, 66, 75, 90, 69, 63, } },
new { student = "Sara", grades = new [] { 55, 58, 63, 70, 55, 55, 76, } },
new { student = "Xavier", grades = new [] { 22, 27, 25, 19, 42, 18, 32, } },
};
Then this should work for you:
var results =
studentGrades
.Select(sg => new
{
sg.student,
average = sg.grades.Average(),
})
.ToArray();

sorting matrix based on columns comparison

I have a matrix of 50 rows and 2 columns and I want to sort them based on the comparison of the value of the second column filed. Here what I mean, if my matrix as:
[00][01]
[10][11]
[20][21]
[30][31]
[40][41]
[50][51]
I want to compare [01] and [11] and if [01] lesser than [11] I want to exchange the entire second row with the first row, to be like this (for example):
[10][11]
[00][01]
[20][21]
[30][31]
[40][41]
[50][51]
I tried using C# and came up with this algorithm but it didn't work:
int temp1, temp2;
for (int i = 0; i < 50; i++)
{
for (int j = i + 1; j < 2; j++)
{
if (rating[i, j] < rating[i + 1, j])
{
temp1 = rating[i + 1, j - 1];
temp2 = rating[i + 1, j];
rating[i + 1, j - 1] = rating[i, j - 1];
rating[i + 1, j] = rating[i, j];
rating[i, j - 1] = temp1;
rating[i, j] = temp2;
}
}
}
Can someone tell me a key to workout this problem or if you have the answer in c,c++ or another language please share it with us.
Thank you.

I believe you are trying to sort the matrix in descending order of second column. Give this code a try.
int[][] mat = new[] { new[] { 4, 4 }, new[] { 5, 1 }, new[] { 3, 2 }, new[] { 6, 1 } };
var ordered = mat.OrderByDescending(i => i[1]);

Your implementation of sort algorithm is wrong. The inner loop should not run from i+1 to 1.
Try implementing the simple bubble sort:
for (int i = 0; i < 50; i++)
{
for (int j = 0; j < 49-i; j++)
{
if (rating[j, 1] < rating[j + 1, 1]) // column 1 entry comparison
{
temp1 = rating[j, 0]; // swap both column 0 and column 1
temp2 = rating[j, 1];
rating[j, 0] = rating[j+1, 0];
rating[j, 1] = rating[j+1, 1];
rating[j+1, 0] = temp1;
rating[j+1, 1] = temp2;
}
}
}

Sorting by Name (alphabetic) - Dual arrays [duplicate]

This question already has an answer here:
Closed 11 years ago.
Possible Duplicate:
Sorting by Name (alphabetic)
Say I have the code below. I have a total of 6 radio buttons. I have the 5 of the radio buttons working. The last is called radio button is called rbRegion. I believe I have everything set up correctly. There are two arrays, one for strings, and one for 4 quarterly totals and one yearly total. Say I wanted to sort by region name, I would place it in the `if (rbRegion.Checked) area. What exactly would I need to place in there to sort it alphabetically and to change the corresponding numeric array.
private void btnSort_Click(object sender, EventArgs e)
{
int n;
decimal temp;
int sortCol = 0;
string ntemp;
bool swapFlag;
if (rb1.Checked)
sortCol = 0;
if (rb2.Checked)
sortCol = 1;
if (rb3.Checked)
sortCol = 2;
if (rb4.Checked)
sortCol = 3;
if (rbTotal.Checked)
sortCol = 4;
if (rbRegion.Checked)
{
}
else
{
do
{
swapFlag = false;
for (n = 0; n < lastIndexUsed; n++)
{
if(quarters[n,sortCol] < quarters[n+1, sortCol])
{
//column 4
temp = quarters[n, 4];
quarters[n, 4] = quarters[n + 1, 4];
quarters[n+1, 4] = temp;
//col 3
temp = quarters[n, 3];
quarters[n, 3] = quarters[n + 1, 3];
quarters[n + 1, 3] = temp;
//col 2
temp = quarters[n, 2];
quarters[n, 2] = quarters[n + 1, 2];
quarters[n + 1, 2] = temp;
// col 1
temp = quarters[n, 1];
quarters[n, 1] = quarters[n + 1, 1];
quarters[n + 1, 1] = temp;
//col 0
temp = quarters[n, 0];
quarters[n, 0] = quarters[n + 1, 0];
quarters[n + 1, 0] = temp;
//name
ntemp = Branch[n];
Branch[n] = Branch[n + 1];
Branch[n + 1] = ntemp;
swapFlag = true;
}//endif
}//for end
} while (swapFlag);
}

If the value inside the rbRegion.Checked condition is an array. you can use this code.
Array.Sort(YourStringArray); // Ascending
Array.Reverse(YourStringArray); // Descending