How to find the max value of group of arrays

Karthik Agarwal

15y2.2k

Hi,

I have six arrays which is of float type. Any specific index in all these arrays represent set of values for me. Ex: if index is zero all the six arrays zeroth index represent a set of values, from which i need to find the max value. similarly for all other indexes.

array1 array2 array3 array4 array5 array6
0 0 0 0 0 0
1 1 1 1 1 1
-------------------------------------so on

i need to find out which is the max value of a specific index among all these arrays and should store it in another array or list

9 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes15y ago
Accepted answer
This code should do it:

#include "stdafx.h"

using namespace System;

float GetMaximum(array^ array)
{
float max = Single::MinValue;
for each(float f in array)
{
if (f > max) max = f;
}
return max;
}

int main(array ^args)
{
array^ array1 = {1, 2, 3, 4, 5, 6};
array^ array2 = {7, 8, 9, 1, 2, 3};
array^ array3 = {1, 2, 3, 10, 11, 12};
array^ array4 = {-1, -2, -3, -4,-5, -6};
array^ array5 = {-7, -8, -9, -3, -4, -5};
array^ array6 = {4, 5, 6, -1, -2, -3};
array^ maxima = gcnew array(6);
maxima[0] = GetMaximum(array1);
maxima[1] = GetMaximum(array2);
maxima[2] = GetMaximum(array3);
maxima[3] = GetMaximum(array4);
maxima[4] = GetMaximum(array5);
maxima[5] = GetMaximum(array6);

// check it worked
Console::WriteLine("The maxima are \n");
for each(float f in maxima) Console::WriteLine(f);
Console::ReadKey();
return 0;
}
0
Vulpes15y ago
Just realized that I've programmed the wrong problem!

Instead of generating an array consisting of the maxima of the other 6 arrays, you asked for an array whose i'th element contains the maxima of the i'th elements of the other 6 arrays.

With apologies for the confusion, here's the revised code:

#include "stdafx.h"

using namespace System;

array^ GetMaxima(array^>^ arrayOfArrays)
{
array^ maxima = gcnew array(arrayOfArrays[0]->Length);

for(int i = 0; i < maxima->Length; i++)
{
float max = Single::MinValue;

for(int j = 0; j < arrayOfArrays->Length; j++)
{
if (arrayOfArrays[j][i] > max) max = arrayOfArrays[j][i];
}

maxima[i] = max;
}

return maxima;
}

int main(array ^args)
{
array^ array1 = {1, 2, 3, 4, 5, 6};
array^ array2 = {7, 8, 9, 1, 2, 3};
array^ array3 = {1, 2, 3, 10, 11, 12};
array^ array4 = {-1, -2, -3, -4,-5, -6};
array^ array5 = {-7, -8, -9, -3, -4, -5};
array^ array6 = {4, 5, 6, -1, -2, -3};
array^>^ arrayOfArrays = {array1, array2, array3, array4, array5, array6};
array^ maxima = GetMaxima(arrayOfArrays);
// check it worked
Console::WriteLine("The maxima are \n");
for each(float f in maxima) Console::WriteLine(f);
Console::ReadKey();
return 0;
}
0
Vulpes15y ago
Although the OP hasn't asked for it, I agree that it would be better to use a 2D array rather than 6 single dimensional arrays.

Here's the C++/CLI code for that:

#include "stdafx.h"

using namespace System;

array^ GetMaxima(array^ array2D)
{
array^ maxima = gcnew array(array2D->GetLength(0));
for(int i = 0; i < array2D->GetLength(0); i++)
{
float max = Single::MinValue;
for(int j = 0; j < array2D->GetLength(1); j++)
{
if (array2D[i, j] > max) max = array2D[i, j];
}
maxima[i] = max;
}
return maxima;
}

int main(array ^args)
{
array^ array2D =
{
{1, 2, 3, 4, 5, 6},
{7, 8, 9, 1, 2, 3},
{1, 2, 3, 10, 11, 12},
{-1, -2, -3, -4,-5, -6},
{-7, -8, -9, -3, -4, -5},
{4, 5, 6, -1, -2, -3}
};

array^ maxima = GetMaxima(array2D);

// check it worked
Console::WriteLine("The maxima are \n");
for each(float f in maxima) Console::WriteLine(f);
Console::ReadKey();
return 0;
}
0
Sam Hobbs15y ago
I hope that Karthik answers my question so we don't need to speculate. Using managed code, it is relevant to suggest use of a two-dimensional array. I assume there is an array operation that could be used but even a simple foreach would help but certainly (I assume) LINQ could be used with a two-dimensional array. Using the C++ Standard Library, it is possible to use a vector of vectors and perhaps a member of the Members (Standard C++ Library) would help.

Also for C++ the Boost web site has an abundance of additional classes that can help. The Boost web site says that ten of the Boost libraries are in the new C++ standard. So it is likely that it is possible to use a library that is even more mature than the existing C++ Standard Library to write code now that will be compatible with the new standard.
0
Vulpes15y ago
Suthish,

The only ones I'm reasonably fluent in nowadays are C#, C++ and VB though I have used several others in my time.

Sam,

Judging by the OP's previous thread, he's using C++/CLI.
0
Sam Hobbs15y ago
Suthish: Depending on the definition of "know" and "language" I know many languages. I won't get into that here, since it is off-topic.
0
Sam Hobbs15y ago
Do you need managed or unmanaged code?

Is this a class assignment? It sure sounds like one.

You might consider making a two-dimensional array and then you can use existing methods to access the set of values instead of writing a line of code for each one of the six values.
0
Suthish Nair15y ago
Hi Vulpes, How are you.. How many languages you knows :)
0
Jaganathan Bantheswaran15y ago
Hi,

Store those specific index values in one array and compare that array value.
0