The Program does not provide any output. Can't figure out why...

[Captain Neo]

#include<iostream.h>
#include<conio.h>
#include<math.h>
void main()
{   clrscr();
    int n,x,i,j;
    float p,fact=1.0,sum=0.0;
    cout<<"\n\tEnter the number: ";
    cin>>n;
    cout<<"\n\n\tEnter the Value of \'x\': ";
    cin>>x;

    for(i=1;i<=n;i++)
    {   for(j=(2*j-1);j>0;j--)
           { fact=j*fact;
            if(i%20==0)
               p=(-1)*pow(x,(2*i-1));
            else
               p=pow(x,(2*i-1));
            sum+=p/fact;
           }
    }
    cout<<"\n\tThe sum is "<<sum;

    getch();
}

[Clinton Portis]

One problem may be that you never initialized any of your variables.

//These could literally be any value.
int n,x,i,j;

Here you create a variable 'j', and make a whole bunch of loop conditions that are based on 'j'... 'j' could be anything......

for([B]j[/B]=(2*[B]j[/B]-1);[B]j[/B]>0;[B]j[/B]--)

[richieking]

can you please put your code into the code tags?

[PrimePackster]

Captain Neo! Use the code tag.

[PrimePackster]

Well here is the code(Not edited) in code tag.

/*x-(x^3/3!)+(x^5/5!)-(x^7/7!).......*/

#include<iostream.h>
#include<conio.h>
#include<math.h>
void main()
{	clrscr();
	int n,x,i,j;
	float p,fact=1.0,sum=0.0;
	cout<<"\n\tEnter the number: ";
	cin>>n;
	cout<<"\n\n\tEnter the Value of \'x\': ";
	cin>>x;

	for(i=1;i<=n;i++)
	{	for(j=(2*j-1);j>0;j--)
		   { fact=j*fact;
		    if(i%20==0)
		       p=(-1)*pow(x,(2*i-1));
		    else
		       p=pow(x,(2*i-1));
		    sum+=p/fact;
		   }
	}
	cout<<"\n\tThe sum is "<<sum;

	getch();
}

[richieking]

To use only cout... you need to add the namespace.

using namespace std;

or

std::cout<<foo;

[PrimePackster]

To use only cout... you need to add the namespace.

using namespace std;

or

std::cout<<foo;

I think he is using pretty much an old compiler, most probably Turbo C++ conio.h & clrscr() points to that. So i think he don't need to use namespace std, since it applies to modern compilers only.

[PrimePackster]

Problem seems to be with the nested loop,

for(i=1;i<=n;i++)
	{	for(j=(2*i-1);j>0;j--) //Changed j to i
		    fact=j*fact;
		    if(i%2==0) //changed 20 to 2.
		       p=(-1)*pow(x,(2*i-1));
		    else
		       p=pow(x,(2*i-1));
		    sum+=p/fact; //Deleted those braces

		   
	}

Now that should work.......