function to calculate maximum value

suchi_s · 10-26-2004, 07:35 AM

maximum value from the column in the file
45
34
67
89
89
90
the ans should be 90
is there any function in linux to calculate the maximum value

clb · 10-26-2004, 07:55 AM

I dont know of any function, but it wouldnt be too hard to parse it yourself.

Code:

Psuedocode:

        function ParseFile()
        {
                int NumberOfItems = 0;
                Parse through the file and get he number of items in the column

                return(NumberOfItems);
        }

        function main()
        {
                const ArraySize = ParseFile();

                int HighestValue = 0; //The highest value will be stored here
                int NumberArray[ArraySize]; //The array to store the column

                        for(int i=0; i=ArraySize;i++)
                        {
                                if NumberArray[i]>=HighestValue
                                {
                                        HighestValue = NumberArray[i];
                                }
                        }

                        printf("The higest value was %d",HighestValue);
                }

There are probably easier, more efficient ways of doing it but I havent had much sleep. There are probably some syntax errors there, so dont take it as working code, just a base that should help.

Chris

suchi_s · 10-26-2004, 08:13 AM

but how to initalise the array NumberArray as its values are stored in a file

clb · 10-26-2004, 10:17 AM

This code works:

Code:

#include <iostream>
#include <fstream.h>
#include <ctype.h>
using namespace std;

int parseFile(char filename[80]);
int Highest();

int parseFile(char filename[80])
{
	int intNumberOfElements = 0; //The total number of elements in the the file
	ifstream fin(filename);    // Open the file passed to this function for reading
	string temp; //Where we store the string we ouput from the file

		cout << "Getting Total Number Of Elemnents...."<<endl;
		while (getline(fin,temp))
		{	
			intNumberOfElements++; //Add one to the total
		}
		fin.close(); //Close the file
		cout << "Done"<<endl;
		
	return(intNumberOfElements);
}

int Highest()
{
	char filename[80]; //The file you want to open
	int HighestValue = 0; //This will store the largest value from the text file
	
	string temp; //Where we store the string we ouput from the file
	int i = 0; //The loop counter
	
	cout  << "File: "; //Ask for a filename
	cin >> filename;
	
	const int NumberOfElements = parseFile(filename); //Declare a constant with the number of elements in the file so we can create an array
	cout << "Elements: " << NumberOfElements << endl;  //Tell the user how many elements there are
	int intNumberArray[NumberOfElements]; //Create the array
	ifstream fin(filename);    // Open the file passed to this function for reading
	//Fill the array
	cout << "Filling Array...."<<endl;
		while (getline(fin,temp))
		{
			intNumberArray[i] = atoi(temp.c_str()); //Add the current line nto the array
			i++; //Add one to the total
		}
	cout << "Done"<<endl;
	cout << "Checking for highest value...."<<endl;
	for(i = 0; i < NumberOfElements; i++)
	{
		if(intNumberArray[i]>=HighestValue)
		{
			HighestValue=intNumberArray[i];
		}
	}
	fin.close(); //Close the file again
	cout << "Done...."<<endl;
	return(HighestValue);
}

All you need to do is include the two functions in your source files, and the right header files. To get the highest value you just need to have the following in the funtion that calls the ones to find the highest number:

Code:

int HighestNumber = Highest;
cout << HighestNumber

Hope that helps,
Chris

EDIT:
Testing this I used a file in the same directory as the executable. The file should be formatted like:

Code:

i.e. with each number on a new line.

jordanGSU · 10-26-2004, 10:23 AM

Do you need to store all the values in an array?
if not, just have a max variable thats initialized to zero...read in each value one by one....if the value if larger than the max, set max to that.
code would be considerably shorter if you could do that.

clb · 10-26-2004, 10:38 AM

Lol, yeah it would be shorter and more effiecient, it just didnt occur to me not to use an array.
It depends if you want access to each individual number afterwards or not I guess.
If you just want the highest number in the list, then use this code:

Code:

#include <iostream>
#include <fstream.h>
#include <ctype.h>
using namespace std;

int Highest();

int Highest()
{
	char filename[80]; //The file you want to open
	int HighestValue = 0; //This will store the largest value from the text file
	int tempint = 0; //This will store the converted temp variable
	string temp; //Where we store the string we ouput from the file
	cout  << "File: "; //Ask for a filename
	cin >> filename;
	ifstream fin(filename);    // Open the file passed to this function for reading
	cout << "Processing File...."<<endl;
	while (getline(fin,temp))
	{	
		tempint = atoi(temp.c_str());
		if (tempint>=HighestValue)
		{
			HighestValue=tempint;
		}
	}
	fin.close(); //Close the file again
	cout << "Done...."<<endl;
	return(HighestValue);
}

Use it in the same way as I described before.
Chris