Question about improving solutions

[zacblazic]

Hey guys,

My lecturer told me that when I have solved a problem, I should always look for ways to improve it.

I was wondering if it is okay to post my code here and ask the community to comment and tell me if it can be improved, but I don't want to be told how. Hints are welcome though.

Problem: Find the minimum and maximum of each column and row of a 2D array.

I have spent about 1 hour so far and it works. This problem did confuse me with all the min's and max's.

I was thinking it could be done in one set of for loops, but I'm not sure.

Heres my code:

#include <iostream>
#include <ctime>

using namespace std;

struct MinMax
{
	int min;
	int max;
};

void initializeArray(int randomArray[][5]);
void determineRowMinMax(int randomArray[][5], MinMax rowMinMax[]);
void determineColMinMax(int randomArray[][5], MinMax colMinMax[]);
void displayArray(int randomArray[][5]);
void displayMinMax(MinMax rowMinMax[],  MinMax colMinMax[]);

void main()
{
	//No constant declarations

	//Variable declartions

	int randomArray[5][5];
	MinMax rowMinMax[5];
	MinMax colMinMax[5];

	//Executable statements

	initializeArray(randomArray);
	determineRowMinMax(randomArray, rowMinMax);
	determineColMinMax(randomArray, colMinMax);
	displayArray(randomArray);
	displayMinMax(rowMinMax, colMinMax);
}

void initializeArray(int randomArray[][5])
{
	srand(unsigned(time(0)));

	for(int row = 0; row < 5; row++)
	{
		for(int col = 0; col < 5; col++)
		{
			randomArray[row][col] = (rand() % 9) + 1;
		}
	}
}

void determineRowMinMax(int randomArray[][5], MinMax rowMinMax[])
{
	for(int row = 0; row < 5; row++)
	{
		rowMinMax[row].min = randomArray[row][0];
		rowMinMax[row].max = randomArray[row][0];

		for(int col = 0; col < 5; col++)
		{
			if(randomArray[row][col] < rowMinMax[row].min)
			{
				rowMinMax[row].min = randomArray[row][col];
			}
			
			if(randomArray[row][col] > rowMinMax[row].max)
			{
				rowMinMax[row].max = randomArray[row][col];
			}
		}
	}
}

void determineColMinMax(int randomArray[][5], MinMax colMinMax[])
{
	for(int col = 0; col < 5; col++)
	{
		colMinMax[col].min = randomArray[0][col];
		colMinMax[col].max = randomArray[0][col];

		for(int row = 0; row < 5; row++)
		{
			if(randomArray[row][col] < colMinMax[col].min)
			{
				colMinMax[col].min = randomArray[row][col];
			}

			if(randomArray[row][col] > colMinMax[col].max)
			{
				colMinMax[col].max = randomArray[row][col];
			}
		}
	}
}

void displayArray(int randomArray[][5])
{
	for(int row = 0; row < 5; row++)
	{
		for(int col = 0; col < 5; col++)
		{
			cout << randomArray[row][col] << " ";
		}
		cout << endl;
	}
}

void displayMinMax(MinMax rowMinMax[],  MinMax colMinMax[])
{
	cout << "\n    Min   Max" << endl;
	for(int i = 0; i < 5; i++)
	{
		cout << "R" << i + 1 << ": "  << rowMinMax[i].min << "     " << rowMinMax[i].max << endl;
	}

	for(int i = 0; i < 5; i++)
	{
		cout << "C" << i + 1 << ": " << colMinMax[i].min << "     " << colMinMax[i].max << endl;
	}
}

[Kanoisa]

Hi, Have you considered combining your code for the row and column minimum and maximum checks into one function?

[zacblazic]

Ah true, thanks I will do that. But there are still two sets of loops going on.

[Kanoisa]

Im sure you can if you think about it get both row and cols min and max from just the loops in one function you dont need to do the same nested loop 2 times

[zacblazic]

It must be possible to do that right? Can anyone confirm?

[anilashanbhag]

yes it is very much possible

[zacblazic]

I think I have done it:

void determineMinMax(int randomArray[][SIZE], MinMax rowMinMax[], MinMax colMinMax[])
{
	for(int row = 0; row < SIZE; row++)
	{
		rowMinMax[row].min = randomArray[row][0];
		rowMinMax[row].max = randomArray[row][0];

		for(int col = 0; col < SIZE; col++)
		{
			if(row == 0)
			{
				colMinMax[col].min = randomArray[0][col];
				colMinMax[col].max = randomArray[0][col];
			}

			if(randomArray[row][col] < rowMinMax[row].min)
			{
				rowMinMax[row].min = randomArray[row][col];
			}

			if(randomArray[row][col] > rowMinMax[row].max)
			{
				rowMinMax[row].max = randomArray[row][col];
			}

			if(randomArray[row][col] < colMinMax[col].min)
			{
				colMinMax[col].min = randomArray[row][col];
			}

			if(randomArray[row][col] > colMinMax[col].max)
			{
				colMinMax[col].max = randomArray[row][col];
			}
		}
	}
}

What do you think?

[anilashanbhag]

seems like the right one - essentially a 2d array n*4 elems [4- row max/min column max/min ] updated for each elem