Programming Forums > Application Development > C++

Simplesouljah · Dec 4th, 2007, 4:09 PM

having a problem with a program not sure what I'm doing wrong. I to write this program that
inputs integer data from a file into an array of size 100. We have to create a
variable to keep track of how many numbers were read into the array, then
determine where in the array the highest and lowest value reside.

here's what I have so far...

 c++ Syntax (Toggle Plain Text) 
#include <iostream>
#include <fstream>
#include <string>
 
 
using namespace std;
 
int main()
{
    int i, max, min, maxNumber, minNumber;
    string myArray;
    max = 0;
    min = 0;
 
    ifstream inFile;
    ofstream outFile;
 
    inFile.open ("inputNums.txt");
    outFile.open ("finalResults.txt");
 
    inFile >> myArray;
 
    for (i = 0; i <= 100; i++)
         {   inFile >> myArray[i];
 
 
    outFile << "The maximum value is " << max << " found at array index position" << endl;
    outFile << endl;
 
    outFile << "The minimun value is " << min << "found at array index position" << endl;
    outFile << endl;
 
    outFile << "There are  " << endl;
    outFile << endl;
 
    outFile << "Thank You!" << endl;
 
    inFile.close();
    outFile.close();
}   
 
 
 system ("pause");
 return 0;
}
#include <iostream>
#include <fstream>
#include <string>


using namespace std;

int main()
{
    int i, max, min, maxNumber, minNumber;
    string myArray;
    max = 0;
    min = 0;
    
    ifstream inFile;
    ofstream outFile;
    
    inFile.open ("inputNums.txt");
    outFile.open ("finalResults.txt");
    
    inFile >> myArray;
    
    for (i = 0; i <= 100; i++)
         {   inFile >> myArray[i];
    
    
    outFile << "The maximum value is " << max << " found at array index position" << endl;
    outFile << endl;

    outFile << "The minimun value is " << min << "found at array index position" << endl;
    outFile << endl;
    
    outFile << "There are  " << endl;
    outFile << endl;
    
    outFile << "Thank You!" << endl;
    
    inFile.close();
    outFile.close();
}   
    
    
 system ("pause");
 return 0;
}

Ancient Dragon · Dec 4th, 2007, 4:28 PM

line 11:
myArray is not an int array. It needs to be declared like this:

(Toggle Plain Text)

int myArray[100] = {0};

line 23: do not make the assumption that the file contains 100 integers -- maybe it only contains 10, maybe it contains a million. The idea is to read the file until end-of-file is reached or your array is filled up, whichever somes forst. So the way to code that loop is like this:

(Toggle Plain Text)

while( inFile >> myArray[i]) 
    ++i;

max. To find the max value, just keep track of the maximum value as they are being read from the file

(Toggle Plain Text)

int max = -1000;
int i = 0;
while( inFile >> myArray[i]) 
{
    if( myArray[i] > max)
         max = myArray[i];
    ++i;
}

Simplesouljah · Dec 4th, 2007, 4:38 PM

what about the min value? do i use the else if statement?

Simplesouljah · Dec 4th, 2007, 4:39 PM

c++'
int i, min = nums[0 Syntax (Toggle Plain Text)

, max = min;
        for(i = 1; i < size; ++i)
        {
                if (nums[i] < min)
                        min = nums[i];
                else if (nums[i] > max)
                        max = nums[i];
        }

can I do it like this?

Ancient Dragon · Dec 4th, 2007, 4:42 PM

>>do i use the else if statement
No, just use another variable and statement like I did for the max value. I wouldn't use the else statement because maybe the current value just read affects both min and max.

(Toggle Plain Text)

int max = 0;
int min = 0;
int i = 0;
while( inFile >> myArray[i]) 
{
     if( i == 0) // first time throug
    {
         max = min = myArray[i];
    }
    if( myArray[i] > max)
         max = myArray[i];
    if( myArray[i] < min)
         min = myArray[i];
    ++i;
}

And you forgot to add code tags

Simplesouljah · Dec 4th, 2007, 4:46 PM

I'm sorry about the code tags...I'm a newbie, still learning

Simplesouljah · Dec 4th, 2007, 4:52 PM

I'm sorry.....I am so lost....do I need lines 10-13? and where would I place the

(Toggle Plain Text)

int max = [-1000];
int i = [0];
while( inFile >> myArray[i]) 
{
    if( myArray[i] > max)
         max = myArray[i];
    ++i;
}

also what is the code tags?

Ancient Dragon · Dec 4th, 2007, 5:08 PM

>>do I need lines 10-13?
yes. But you need to change line 11 as I said previously.

>>where would I place this
replace lines 23 and 24 with the lines that were in my most post #5

>>also what is the code tags?
Read your PM that I sent you. It shows you how to do it.

Simplesouljah · Dec 4th, 2007, 5:14 PM

didn't get the PM?

Ancient Dragon · Dec 4th, 2007, 5:19 PM

Quote:

Originally Posted by Simplesouljah

didn't get the PM?

Oh, I thought you would have received one. Then read the Read Me threads at the top of this board -- I just finished adding a new one that shows how to use code tags.

Dec 4th, 2007, 4:09 PM	#1
Simplesouljah Newbie Join Date: Oct 2007 Posts: 28 Rep Power: 0	read integers from file into an array having a problem with a program not sure what I'm doing wrong. I to write this program that inputs integer data from a file into an array of size 100. We have to create a variable to keep track of how many numbers were read into the array, then determine where in the array the highest and lowest value reside. here's what I have so far... c++ Syntax (Toggle Plain Text) #include <iostream> #include <fstream> #include <string> using namespace std; int main() { int i, max, min, maxNumber, minNumber; string myArray; max = 0; min = 0; ifstream inFile; ofstream outFile; inFile.open ("inputNums.txt"); outFile.open ("finalResults.txt"); inFile >> myArray; for (i = 0; i <= 100; i++) { inFile >> myArray[i]; outFile << "The maximum value is " << max << " found at array index position" << endl; outFile << endl; outFile << "The minimun value is " << min << "found at array index position" << endl; outFile << endl; outFile << "There are " << endl; outFile << endl; outFile << "Thank You!" << endl; inFile.close(); outFile.close(); } system ("pause"); return 0; } #include <iostream> #include <fstream> #include <string> using namespace std; int main() { int i, max, min, maxNumber, minNumber; string myArray; max = 0; min = 0; ifstream inFile; ofstream outFile; inFile.open ("inputNums.txt"); outFile.open ("finalResults.txt"); inFile >> myArray; for (i = 0; i <= 100; i++) { inFile >> myArray[i]; outFile << "The maximum value is " << max << " found at array index position" << endl; outFile << endl; outFile << "The minimun value is " << min << "found at array index position" << endl; outFile << endl; outFile << "There are " << endl; outFile << endl; outFile << "Thank You!" << endl; inFile.close(); outFile.close(); } system ("pause"); return 0; } Last edited by Ancient Dragon; Dec 4th, 2007 at 4:24 PM. Reason: add code tags

Dec 4th, 2007, 4:28 PM	#2
Ancient Dragon PFO God In Training Join Date: Jun 2005 Location: near St Louis, MO. (USA) Posts: 529 Rep Power: 4	Re: read integers from file into an array line 11: myArray is not an int array. It needs to be declared like this: (Toggle Plain Text) int myArray[100] = {0}; int myArray[100] = {0}; line 23: do not make the assumption that the file contains 100 integers -- maybe it only contains 10, maybe it contains a million. The idea is to read the file until end-of-file is reached or your array is filled up, whichever somes forst. So the way to code that loop is like this: (Toggle Plain Text) while( inFile >> myArray[i]) ++i; while( inFile >> myArray[i]) ++i; max. To find the max value, just keep track of the maximum value as they are being read from the file (Toggle Plain Text) int max = -1000; int i = 0; while( inFile >> myArray[i]) { if( myArray[i] > max) max = myArray[i]; ++i; } int max = -1000; int i = 0; while( inFile >> myArray[i]) { if( myArray[i] > max) max = myArray[i]; ++i; }

Dec 4th, 2007, 4:38 PM	#3
Simplesouljah Newbie Join Date: Oct 2007 Posts: 28 Rep Power: 0	Re: read integers from file into an array what about the min value? do i use the else if statement?

Dec 4th, 2007, 4:39 PM	#4
Simplesouljah Newbie Join Date: Oct 2007 Posts: 28 Rep Power: 0	Re: read integers from file into an array c++' int i, min = nums[0 Syntax (Toggle Plain Text) , max = min; for(i = 1; i < size; ++i) { if (nums[i] < min) min = nums[i]; else if (nums[i] > max) max = nums[i]; } , max = min; for(i = 1; i < size; ++i) { if (nums[i] < min) min = nums[i]; else if (nums[i] > max) max = nums[i]; } can I do it like this? Last edited by Ancient Dragon; Dec 4th, 2007 at 4:43 PM. Reason: you forgot the code tags -- for the second time.

Dec 4th, 2007, 4:46 PM	#6
Simplesouljah Newbie Join Date: Oct 2007 Posts: 28 Rep Power: 0	Re: read integers from file into an array I'm sorry about the code tags...I'm a newbie, still learning

Dec 4th, 2007, 4:42 PM	#5
Ancient Dragon PFO God In Training Join Date: Jun 2005 Location: near St Louis, MO. (USA) Posts: 529 Rep Power: 4	Re: read integers from file into an array >>do i use the else if statement No, just use another variable and statement like I did for the max value. I wouldn't use the else statement because maybe the current value just read affects both min and max. (Toggle Plain Text) int max = 0; int min = 0; int i = 0; while( inFile >> myArray[i]) { if( i == 0) // first time throug { max = min = myArray[i]; } if( myArray[i] > max) max = myArray[i]; if( myArray[i] < min) min = myArray[i]; ++i; } int max = 0; int min = 0; int i = 0; while( inFile >> myArray[i]) { if( i == 0) // first time throug { max = min = myArray[i]; } if( myArray[i] > max) max = myArray[i]; if( myArray[i] < min) min = myArray[i]; ++i; } And *you forgot to add code tags*

Dec 4th, 2007, 4:52 PM	#7
Simplesouljah Newbie Join Date: Oct 2007 Posts: 28 Rep Power: 0	Re: read integers from file into an array I'm sorry.....I am so lost....do I need lines 10-13? and where would I place the (Toggle Plain Text) int max = [-1000]; int i = [0]; while( inFile >> myArray[i]) { if( myArray[i] > max) max = myArray[i]; ++i; } int max = [-1000]; int i = [0]; while( inFile >> myArray[i]) { if( myArray[i] > max) max = myArray[i]; ++i; } also what is the code tags? Last edited by Ancient Dragon; Dec 4th, 2007 at 5:10 PM. Reason: Third time I added code tags

Dec 4th, 2007, 5:08 PM	#8
Ancient Dragon PFO God In Training Join Date: Jun 2005 Location: near St Louis, MO. (USA) Posts: 529 Rep Power: 4	Re: read integers from file into an array >>do I need lines 10-13? yes. But you need to change line 11 as I said previously. >>where would I place this replace lines 23 and 24 with the lines that were in my most post #5 >>also what is the code tags? Read your PM that I sent you. It shows you how to do it.

Dec 4th, 2007, 5:14 PM	#9
Simplesouljah Newbie Join Date: Oct 2007 Posts: 28 Rep Power: 0	Re: read integers from file into an array didn't get the PM?

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Programming Forums > Application Development > C++

read integers from file into an array