Posts by computer engW

Thank you for all your replies....

Could any one answer my questions??

Thanks so much.

Here i have problem with ctype.h library .I think i use correctly,but i ahve an error on it.
This is the code.

#include<iostream>
#include <ctype.h>
using namespace std;
int main(){
	char letter;
	int num;
	int isdigit(int letter);
	int  isupper (int letter);
	int islower( int letter);
	int small=0;
	int capital=0;
	int number=0;
	int special=0;

	 cout<<"Enter any number and letter you like,'+'means   exit";
	 /* use if statement to help user to count how many times s/he enter letter*/
   for(int i=0;i<=5;i++)  //any number greater than one
	{     //start while here
	

	  cin>>letter; //user enter a number
	  if (letter==isdigit(letter))
		  number++;
	  if(letter==isupper(letter))
		capital++;  //counting capital letter
	  else  if(letter==islower(letter))
		  small++;  //in case enter small, letter counting small letter
	  
	  else if(letter!=isupper(letter) && letter!=islower(letter) && num!=isdigit(num))
		  special++;  /*if the user enter a sepcial                                    chraecter*/

   }
	  
	
	

      cout<<number<<endl<<small<<endl<<capital<<endl<<special;
return 0;
}

You can also see this URL http://www.daniweb.com/forums/thread67837.html

thekashyap wrote some problems(1,2,3) they related to graohs .

Right, well, I'm not sure I understand what you are asking...

Which shapes do you need to learn how to draw? Just a square/triangle? That would be where I would start...

So what do you mean by math calculations?

Please look to this code

#include <iostream>
using namespace std; // So the program can see cout and endl

int main()
{
int n = 4;
int line, stars, loop;
for (line = 1; line <= n; line++)
{
                   stars = n - line + 1;
    for (loop = 1; loop <= stars; loop++)
        cout << "*";
    cout << endl;
}
}

they use a simple math colculation stars = n - line + 1; in order to output the shape.However, i think there are a relationship between some shapes -correct me if iam wrong-
Which shapes i'd like to learn like differnt shapes of triangle ,sequsre, rectangle ,but i guess that triangle shapes will be come on the exam ^_^

Thank you so much,but i have problem with another prgram i will post it here.

Thanks again

Or else you do a few math calculations, then set up a function to draw individual shapes....

For example, you could create a "square" function:

void draw_square(int sideLength);

which basically loops and outputs a square (of the specified size, using a loop) to the screen...

Advantage: you can create reusable shape-builders...to make more shapes...haha

EDIT: niek_e is right, what specifically do you need help with, rather than us just posting code...

Could you tell me how can i use Math caculations to write these kind iof codes.
Becus sometime i found in other wbsites they use Math calculations.

There's isn't a magic code to draw 'all shapes'
I guess this is a homework assignment to learn loops?
If yes: Post your attempt here (are tell us what part you don't understand), and you'll get help.
if no: The easiest way to draw the shape in your post is: std::cout << "*****\n****\n***\n**\n*";

Our doctor want us learn how to make these shapes by using loops for exam question.She gave us a question ,we should use loop when solving it.

#include <iostream>
using namespace std; // So the program can see cout and endl

int main()
{
int n = 4;
int line, stars, loop;
for (line = 1; line <= n; line++)
{
                   stars = n - line + 1;
    for (loop = 1; loop <= stars; loop++)
        cout << "*";
    cout << endl;
}

}
The shape will be the same as what i draw.

Hi,
When i write any code has if else statement , and run it na error appeatrs and say that else doesn't match with if or illegal else without matching if.
I don't know where is the problem exctly ,and you should know that i don't put } in these program.
For example this program-

#include<iostream>
using namespace std;
int main(){  
	int year ,month,day,leapyear;
	cout<<"Enter a year and month ";
	cin>>month>>year;
	if ((year % 4 == 0) && ((year % 100 != 0) || (year % 400 == 0))){
		leapyear=1;
	   cout<<"This is aleap year";
	   else{
	   cout<<"This is not leap year";
	   }
	}
return 0;
}

Hi everyone,

Today i have a question about how can i write one code for all shapes like, ******
*****
****
***
**
*

or other shapes like square or tringle.

I want to know the difference in every code.
Thanks alot.

I try to solve this question in two ways,but it didn't work as i want .
1'st way

#include<iostream>
using namespace std;
int main(){
    int value,newvalue;
    cout<<"Enter a number ,and -1 means exit:  ";
    cin>>value;
    do
    {
    cout<<"Enter a new value : ";
    int newvalue;
    cin>>newvalue;
    if(newvalue>value)
    {
      cout<<value;
    }//end of if
    else{
      cout<<"  ";
    }//end of else
    value=newvalue;


    }//end of do
    while(value!=-1);

return 0;

}

I always ask the user to enter new value and that not what i want .

2'nd way:

#include<iostream>
using namespace std;
int main(){
    int value,newvalue;
    cout<<"Enter a number ,and -1 means exit:  ";
    cin>>value;
    cout<<"Enter a new value : ";
    cin>>newvalue;
    while(value!=-1);
    {

    if(newvalue>value)
    {
      cout<<value;
    } //end of if
    else{
      cout<<"  ";
    } //end of else
    value=newvalue;


    } //end of do


return 0;

}

It asks user to enter a value and new value once ,after that it stopped.
One thing i can't understand it and is why the program do not do (value=newvalue)?in both program.

Now that your code is in the shape in which it compiles properly, you can start testing your programs to see if they work as expected.

Thanks alot i will run it and if i have any problem i will tell you ,otherwise i will mark this Thread as solved.

Thanks again

Thanks alot.
I will be more careful about braces {}.

Do i have another mistakes??

Hi mitrmkar ;
I am afriad i don't know what do you mean by (icode/icode).?
However,
I have another 2 questions and there solutions,please if anyone see any mistakes tell me.
Q4 : Starting with the first value of a list (ending with -1) print only the sub-list of values in increasing order.
Example:
Input: 1 4 2 7 3 9 6 -1
Output: 1 4 7 9
Solution:

#include<iostream>
using namespace std;
int main(){
	int value,newvalue;
	cout<<"Enter 2 numbers ,and -1 means exit:  ";
	cin>>value>>newvalue;
	do
	{
	if(newvalue>value)
	  cout<<value;
	else
	  cout<<"  ";
	value=newvalue;
	
	 
	}
	while(value!=-1);

return 0;

}

After i write newvalue the compiler run with out any result,only blank screen.

Q 5:Write a program that accepts a positive integer and gives its prime factorization; that is expresses the integer as a product of primes or indicates that it is a prime.
Solution:

#include<iostream>
using namespace std;
int main(){

	cout<<"Enter any number: ";
	int n;
	cin>>n;
	int i=2;
	while(i<=n)
	{
	if(n%i==0)
	  cout<<i<<"*";
	  n=n/i;
	else  i++;
	 }
	cout<<n;
return 0;
}

In this program i have an error is( expected ';'before "else") ,but i can't understand this error because it is clear that i put semi colon.

Thanks alot.

Could any one help me????

I did small changes in Q1,

#include<iostream>
using namespace std;
int main(){
	int value,check=1;
	cout<<"Enter a number:  ";
	cin>>value;
	while(value>=0)
	{
	int newvalue;
	cout<<"Enter another value:  ";
	cin>>newvalue;
	if(value>newvalue)
	  cout<<" is increasing";
	  check=0;
	  value=-5;
	else
	value=nwvalue;
	if(check==1)
	value==-5
	  cout<<" this is  not increasing order";
        else
	cout<<"This is increasing order";
	}

return 0;
}

Today I have some question and their solution ,but I have problem with some.

Q1: Write a program that checks if a sequence of positive numbers is in increasing order or not.
I don't know what is missing her?!

Solution:

#include<iostream>
using namespace std;
int main(){
	int value,check=1;
	cout<<"Enter a number:  ";
	cin>>value;
	while(value>=0)
	{
	int newvalue;
	cout<<"Enter another value:  ";
	cin>>newvalue;
	if(value>newvalue)
	  cout<<" ....Not sequence";
	  value=-1;
	else
	value=nwvalue;
	if(check==1)
	  cout<<"....is increasing";
	}

return 0;
}

Q 2: Let f(x,n) = x –x3/3! + x5/5! - …+(-1)n x2n+1 /(2n+1)!
Using a loop write a program to calculate f(x,n).

Solution:

#include<iostream>
#include<cmath>
using namespace std;
int main(){
	cout<<"Enter a number ";
	int m;
	cin>>m;
	for(double x=1;x<=m;x++)
	{
	  for(double n=1;n<=x;n++)
	  {
	  n=2*n+1;
	  double fact=1; 
	  fact*=n;
	  double f=1;
	  f=pow(x,n)/fact;
	  cout<<f<<endl;
	  f*=-1;
	  } 
	double f;
	cout<< f<<endl;
	}
	


return 0;
}

Q3: Write a program that prints all possible combinations of 3 numbers between 1 and n.
After I run the compiler ,the output doesn't stop.
Solution:

#include<iostream>
using namespace std;
int main(){
	cout<<"Enter a number : ";
	int num;
	cin>>num;
	for(int i=1;i<=num-2;i++)
	{
	 cout<<i<<endl;
	
	  for(int j=1;j=num-1;j++)
	  {
	     
	     cout<<j<<endl;
	   
		for(int k=1;k<=num;k++)
	        {
		cout<<k<<endl;
		}
	   }
	 
	}

return 0;
}

Please tell me, What are my mistakes?

Yes ,Of course i know factorial.I think i get your idea .Do you mean that i have to do nested for and one of the for statement calculate the factorial.

About ascii chart i don't have any idea .

Hi Everyone ,
I have 3 questions that need explaination (only explain),then i will try to solve them.

Q1: Let g(x,n) = 1 – x2/2! + x4/4! - … …+(-1)n x2n /(2n)!
Using a loop write a program to calculate g(x,n).

Q2: write a program that accepts a positive integer and gives its prime factorization; that is expresses the integer as a product of primes or indicates that it is a prime.

Q3 is simple if i have numbers ,but in this case i have Character.
Write a program that reads three characters and prints the maximum and the minimum in alphabetical order.

Thanks for your time

I know that it is not hard ,but it needs practice .
Thanks for your reply.

Hi ;
I know how to solve the same problem if i have limit numbers ,but here i have n intergers .How can the compiler understanst me when i need n integers ,like this question:

Write a program that takes an n number of integers and calculates their average.
Using for or while loop!

Thanks . Is that mean i had one mistake"quote"only.
Thanks again..

Hi everone,
Today i have a question has two parts and i did what i undrstood.If threr are mistakes ,please tell me.

The Question is:

father decided to buy a new vehicle. He paid 20,000 QR in cash and the rest will be paid on settlements as follows:
 1500 QR per month for 12 months.
 800 QR per month for 24 months, and
 600 QR per month for 48 months.
Q1: Write a C++ program that asks the user to enter the number of months he wants and calculates the total price of the car.
Q2: Adjust the program so that it gives your father a discount on the total price of the car as follows:
 If the total price of the car is less than 38,500 QR the discount will be 15%.
 If the total price of the car is between 36,500 QR and 40,000 QR the discount will be 17%.

 If the total price of the car exceeds 40,000 QR the discount will be 17%.
The program should give now the total price of the car before and after the discount

My answer is :

#include <iostream>
#include<cmath>
using namespace std;
int main(){
	int month ;
	double price;
	cout<<"Enetre your month "; \\the month has to be 12,24 or 48  
	cin>>month ;
	if (month ==12)  
	   cout<<"Total price is= "<<(1500*12)+20000=";  \\total price for 12 months
	else if (month  ==24)
	   cout<<"Total price …

Thanks for your help . Now it's work.
Thanks again

Thanks alot BlackJavaBean .
I understood my errer in question two now.
About question one our doctor did not want to see if statement in the program,she wants us to use switch without if statement.

I have some questions ,i can't solve it .The first one is,

Write a C++ program using the switch statement that does exactly what the following program does:

#include <iostream.h>
#include <math.h>
void main ()
{
   float number;
   int choice;
   cout<< "Enter you number";
   cin>> number;
   cout << "Enter your choice: 1=sin, 2=cos, 3=tan,       4=log ";
   cin >> choice;
   // nested if's:
   if (choice < 1  ||  choice > 4) {
      cout << "wrong choice";
   }
else{                           
      if (choice <= 2){                        
         if (choice == 1){
            cout << sin(number);
         }
         else{                     
            cout << cos(number);
         }
      }
else{                        
         if (choice == 3){
            cout << tan(number);
         }
         else{
            cout << log(number);
         }
      }
   }
}

Seconed question is:
-Write an interactive program that computes the area of a rectangle (area= base * height) or a triangle (area=0.5 * base * height) after prompting the user to type the first character of the figure name (R or T). Your program must display an error message to indicate that the user entered a character other than R or T.

My program look like this:

#include <iostream>
using namespace std;
int main()  {
  float base,heigh;
  char R,T;
  cin>>R ,T;
  cin>>base , heigh;
  if  (char== 'R')
     cout<<base * heigh<<"R" ;
  else  if (char=='T')
      cout<<0.5*base*heigh<<"T" ;
  else 
      cout<<"you enter neither R nor T";

 return 0;
}

After i compiled it i have these errors:

four.cpp:8: error: expected primary-expression before "char"
four.cpp:8: error: expected `)' before "char"

Thanks for all the replies. I realy need help in c++ ,so i think i choice best place , that can help me .
Thank you a lot.

I was looking for some websites ,that can help me in C++ becuase i have c++ course this semester .I really like your siteand I hope i can find help and greetingfrom the members.