find the value in the array that is closest in value to the second parameter

jack223 · #1 03-Nov-2005, 16:28

I have no clue where to start on this one.

The function finds the value in the array that is closest in value to the second parameter. For example, if the array had the values {5, -3, 18, 9, 4} andn the second parameter was 11, then the function would return 9.
If two values are equally distant, return either.

this is how i started.

CPP / C++ / C Code:

#include <iostream>
using std::cout;
using std::cin;
using std::endl;

#include <iomanip>
using std::setw;

const int MAX = 10; 

int main()
{
    int Array[MAX] = {2, 3, 4, 5, 7, 10, 12, 15, 18, 20}; 
    int num;


    cout << "The following numbers are the values inside of MyArray: " << endl;
for (int i = 0; i < MAX; i++) 
    
        cout << Array[i] << " ";
        cout << endl;

    cout << "Please enter an integer range beteween 1 to 20: ";
    cin >> num;
    cout << endl;

    cout << "what number from inside of Array[] is the closest to?? " << num << endl;


    return 0;
}

Paramesh · #2 03-Nov-2005, 17:00

Hi Jack,

Please read the guidelines before posting again.
You should insert your code between [c++] and [/c++] tags.
Thank you.

To find the closest value, we must use the abs function.
The abs function will return the absolute value of an integer.

For example, if we have an integer say

CPP / C++ / C Code:

int i = -5;

Then abs(i) will return the absolute value. i.e 5.

Now to the program:
You started in a good way.
Now the variable num holds the user input value.
We should check which number is the closest to the variable num.

Here is the logic:
1. Use two variable difference and index.

CPP / C++ / C Code:

int difference, index;

2. difference is used to hold the difference between the num and the Array[i].
Index is used to hold the position of the number which has the lowest difference.
3. Initialize index to 0. Initialize difference to absolute value of num - Array[0].

CPP / C++ / C Code:

index = 0;
difference = abs( num - Array[0]);

4. In a for loop, check whether difference is greater than absolute value of num - any other number Array[i].
If it is true, then assign difference as the absolute value of num and Array[i] to difference and index to i.

CPP / C++ / C Code:

for( int i = 0; i < MAX; i++ )
{
    if (difference > abs( num - Array [ i ] ))
    {
        difference = abs( num - Array [ i ] );
        index = i;
    }
}

5. At the end, Array[index] will give you the nearest value and difference will give you the lowest difference.

Regards,
Paramesh.

jack223 · #3 04-Nov-2005, 07:41

Paramesh,

your code doesn't work.

Array[MAX} = {2,3,4,5,7,10,12,15,18,20};

if the user enters num = 13
i'll get index = 6, difference = 1....instead of index = "12".

any suggestion??

Paramesh · #4 04-Nov-2005, 07:45

Hi Jack,

It works correctly.

What is index? it is the position of the array.

So, index = 6 means

Array[6] = 12!

it is correct isnt it?

Regards,
Paramesh.

jack223 · #5 04-Nov-2005, 07:58

oh..i c...thanks

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Rate This Thread
Rate This Thread:

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Pointer Usage in C++: Beginner to Advanced	varunhome	C++ Forum	0	19-Aug-2005 10:25
Help with syntax errors	PeteGallo	C Programming Language	7	08-Aug-2005 21:30
template comiling problems - need expert debugger!	crq	C++ Forum	1	01-Feb-2005 22:26
Re: Programming Techniques	WaltP	C Programming Language	0	10-Mar-2004 00:56

find the value in the array that is closest in value to the second parameter

Re: find the value in the array that is closest in value to the second parameter

Re: find the value in the array that is closest in value to the second parameter

Re: find the value in the array that is closest in value to the second parameter

Re: find the value in the array that is closest in value to the second parameter