Help Help Help!!!

Woot · 06-30-2009, 08:10 PM

I have a problem i can't seem to solve
Combining While Loops and If Statements
Write a program that reads a series of numbers (doubles) from the user, then prints the mean and the
range.
Notes:
• You do not know ahead of time how many numbers will be in the list.
• When you want to stop entering numbers, enter control‐Z.
• The range is the difference between the lowest and the highest number.
• The numbers will be in the range of 0.0 to 100.0. Ignore any numbers outside of this range.

this is my prompt so far. The average is only the last number not all the cins combine between 0 and 100

Code:

#include <iostream>
#include <string>

using namespace std;

int main ()
{
	double n, sum = 0, count = 0;
	
	while(cin >> n)
	{cin >> n;
		if  ((n >= 0.0) && (n <= 100.0))
		{ 
			++count;
			sum += n;	
		}

		else if (n == '^Z') break;
		
		else
		{
			cout << "out of range: ignored.\n";
		}
	}
	
	cout << "The average is " << sum / count << endl;
	
	
}

tabstop · 06-30-2009, 08:17 PM

You've got too many read statements. (Edit: That is to say, you've got a read statement in your while condition, plus one at the top of the loop.)

Woot · 06-30-2009, 08:32 PM

how do i fix this then?

tabstop · 06-30-2009, 09:08 PM

Remove the extra read statements?

Woot · 06-30-2009, 09:16 PM

which ones are the extra read statment

tabstop · 06-30-2009, 09:30 PM

Quote:

Originally Posted by Woot

which ones are the extra read statment

So, trace through your program by hand. Take a list of numbers as input, say "1 47 36 29 86 55 ^Z" and see what happens as your program executes.

legit · 07-01-2009, 07:23 AM

Do you know what your read statements are? I somehow come to the conclusion that you haven't been paying attention in class. :P

WatchTower · 07-01-2009, 08:00 AM

The question is do you know which one is in the expression and which one is not?
Which one are you using to terminate the loop and which one is not used to terminate the loop?

**laserlight** · 07-01-2009, 08:15 AM

This is wrong:

Code:

else if (n == '^Z') break;

The purpose of the instruction to "enter control‐Z" is to simulate end of file, and when end of file is encountered, (cin >> n) evaluates to false, terminating the loop.

hk_mp5kpdw · 07-01-2009, 08:58 AM

FYI, from the forum guidelines:

Quote:

Tips for Efficient and Successful Posting

1. Don't use all caps.

2. Use descriptive subject lines. Do not put URGENT!, or NEED HELP NOW, etc. in your title; it will not make people look at it any faster. Doing this makes many old time helpers on this board not look at the post at all.

Help Help Help!!! does not qualify as a descriptive subject line.

Woot · 07-02-2009, 01:56 PM

can you delete a board post?

**sean** · 07-02-2009, 02:15 PM

We generally don't delete posts because they can be useful for future readers. We'll usually delete inappropriate comments, though.

06-30-2009, 08:10 PM	#1
Woot Registered User Join Date: Jun 2009 Posts: 4	Help Help Help!!! I have a problem i can't seem to solve Combining While Loops and If Statements Write a program that reads a series of numbers (doubles) from the user, then prints the mean and the range. Notes: • You do not know ahead of time how many numbers will be in the list. • When you want to stop entering numbers, enter control‐Z. • The range is the difference between the lowest and the highest number. • The numbers will be in the range of 0.0 to 100.0. Ignore any numbers outside of this range. this is my prompt so far. The average is only the last number not all the cins combine between 0 and 100 Code: #include <iostream> #include <string> using namespace std; int main () { double n, sum = 0, count = 0; while(cin >> n) {cin >> n; if ((n >= 0.0) && (n <= 100.0)) { ++count; sum += n; } else if (n == '^Z') break; else { cout << "out of range: ignored.\n"; } } cout << "The average is " << sum / count << endl; }
Woot is offline

06-30-2009, 08:17 PM	#2
tabstop and the Hat of Guessing Join Date: Nov 2007 Posts: 8,740	You've got too many read statements. (Edit: That is to say, you've got a read statement in your while condition, plus one at the top of the loop.) Last edited by tabstop; 06-30-2009 at 08:23 PM.
tabstop is offline

06-30-2009, 08:32 PM	#3
Woot Registered User Join Date: Jun 2009 Posts: 4	how do i fix this then?
Woot is offline

06-30-2009, 09:08 PM	#4
tabstop and the Hat of Guessing Join Date: Nov 2007 Posts: 8,740	Remove the extra read statements?
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06-30-2009, 09:16 PM	#5
Woot Registered User Join Date: Jun 2009 Posts: 4	which ones are the extra read statment
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07-01-2009, 07:23 AM	#7
legit Student Join Date: Aug 2008 Location: UK -> Newcastle Posts: 156	Do you know what your read statements are? I somehow come to the conclusion that you haven't been paying attention in class. :P __________________ MSDN <- Programmers Haven!
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07-01-2009, 08:00 AM	#8
WatchTower Registered User Join Date: Jul 2009 Posts: 40	The question is do you know which one is in the expression and which one is not? Which one are you using to terminate the loop and which one is not used to terminate the loop?
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07-01-2009, 08:15 AM	#9
laserlight C++ Witch Join Date: Oct 2003 Location: Singapore Posts: 10,359	This is wrong: Code: else if (n == '^Z') break; The purpose of the instruction to "enter control‐Z" is to simulate end of file, and when end of file is encountered, (cin >> n) evaluates to false, terminating the loop. __________________ C + C++ Compiler: MinGW port of GCC Build + Version Control System: SCons + Bazaar Look up a C/C++ Reference and learn How To Ask Questions The Smart Way
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07-02-2009, 01:56 PM	#11
Woot Registered User Join Date: Jun 2009 Posts: 4	can you delete a board post?
Woot is offline

07-02-2009, 02:15 PM	#12
sean Super Moderator Join Date: Sep 2001 Posts: 4,680	We generally don't delete posts because they can be useful for future readers. We'll usually delete inappropriate comments, though.
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