C++ Programming Code Examples

C++ > Algorithms Code Examples

It evaluates the value of any polynomial of any degree, adds two poly



It evaluates the value of any polynomial of any degree, adds two poly
and also multiplies them

Code :

/*evaluates, adds ,multiplies two polynomials p & f to evaluate poly of
deg > 20 manipulate const in size */

#include <iostream.h>
using namespace std ;
void polyadd(float*a,int dega,float*b,int degb,float*sum)
{int i ;
if(dega>=degb)
{for (i=0;i<=dega;i++)
sum[i]=a[i]+b[i] ;}
if(degb >dega)
{for(i=0;i<=degb;i++)
sum[i]= a[i]+b[i] ; }
}
//********************
/*void polymult(float*a,int dega,float*b,int degb,float*mult)
{int i,j;
if(dega<=degb)
for(i=0;i<=degb;i++)
{for(j=0;j<=i;j++)
mult[i]= mult[i] + a[j]*b[i-j]  ;
mult[i] = mult[i] +a[i+1]*b[i+1] ; }
//mult[i] = mult[i] - a[0]*b[0] ; }
if (degb<dega)
{for(i=0;i<=dega;i++)
for(j=0;j<=i;j++)
 mult[i]= mult[i] +a[j]*b[i-j];
mult[i] = mult[i] +a[i+1]*b[i+1] ;} }*/
//**********************

double power(float*a,int n,float x)
{float val=0,prod=1 ;
int i ;
for(i=0;i<=n;i++)
{val = val+a[i]*prod;
prod = prod*x ;}
return val ; }
//******************

double power(float*a,int n,float x);

main()
{const int size=20 ;
int deg,j  ;
float a[size], x ;
for(j=0;j<=size-1;j++)
a[j] = 0.0 ;
double ans ;
cout<<"give the degree of the polynomiala "<<endl ;
cin>>deg ;
if(deg<0)
cout<<"go learn ur textbook"<<endl ;
if(deg>=0)
{
cout<<"give the value of the coefficients"<<endl ;
for (j=0;j<=deg;j++)
cin>>a[j] ;
cout<<"give the value x"<<endl ;
cin>>x ;
ans  = power(a,deg,x);
cout<<"the value of p("<<x<<") = "<<ans <<endl ;
 }

float b[size],sum[size],mult[size],y  ;
for(j=0;j<=size-1;j++)
b[j] = sum[j] = mult[j] = 0 ;
int dega,degb ;
dega = deg ;
/*cout<<"give the value of the coefficients"<<endl ;
for (j=0;j<=dega;j++)
cin>>a[j]; */
cout<<" give in the degree of poly b"<<endl ;
cin>>degb ;
cout<<"enter the values of the coefficient of polynomialb"<<endl ;
for(j=0;j<=degb;j++)
cin>>b[j]  ;
cout<<"give the value to be substituted in polynomialb"<<endl ;
cin>>y ;
ans = power(b,degb,y) ;

cout<<"the value of f("<<y<<") ="<<ans<< endl ;
cout<<"the value of f("<<x<<") ="<<power(b,degb,x)<<endl ;
string decision ;
cout<<"to you want to add or multiply a and b(type a or m) "<<endl ;
cin>>decision ;
if(decision =="a")
{ polyadd(a,dega,b,degb,sum);
if (dega>=degb)
{ans= power(sum,dega,x);
cout<<"the answer after addition of p("<<x<<") +f("<<x<<") 
="<<ans<<endl
;}
if(degb>dega)
{ans = power(sum,degb,x) ;
cout<<"the answer after addition of p("<<x<<") +f("<<x<<") 
="<<ans<<endl
; }}
if (decision=="m")
//{polymult(a,dega,b,degb,mult);
//if (dega>=degb)
{ans= power(a,dega,x)*power(b,degb,y) ;

//cout<<"the answer of multiplication"<<ans<<endl ;}
//if (degb>dega)
//{ ans = power(mult,degb,x) ;
cout<<"the answer after multiplication of p("<<x<<") *f("<<y<<")
="<<ans<<endl ;}
return 0 ;}