HI

I want to add two polynomials

5x^2 - 3xy + y

and

2x^2 - y^2 + 5xy - x + y

using arrays .

I used one array to store the coefficient,power of x ,power of y for the subsequent terms of the 1st polynomial.

a=|5|2|0|-3|1|1|1|0|1|

similary for the other polynomial the array is

b=|2|2|0|-1|0|2|5|1|1|-1|1|0|1|0|1|

Then I copied both the arrays into a third array

c=|5|2|0|-3|1|1|1|0|1|2|2|0|-1|0|2|5|1|1|-1|1|0|1|0|1|

so the 0,3,6,9....elements of array display the coeff.

1,4,7....elements of array display the power of x

2,5,8....elements of array display the power of y

I traversed the array and added the coeff. of the terms having same power of x and y

and then when I try to print the array it is not showing the proper result (showing only the sum of the highest terms)

can anyone point out my mistake ?

Code:

#include <stdio.h>
int main()
{
int a[27],b[27],c[54],m,n,i,j,z,y=0,t,s=0;
printf ("How many terms you want to add in the 1st polynomial ?? : ");
scanf ("%d",&n);
printf ("Enter 1st polynomial : \n");
for (i=0;i<n*3;i=i+3)
{
printf ("Enter coefficient : ");
scanf("%d",&a[i]);
printf ("Enter power of x : ");
scanf("%d",&a[i+1]);
printf ("Enter power of y : ");
scanf("%d",&a[i+2]);
}
printf ("1st polynomial is : ");
for (i=0;i<n*3;i=i+3)
{
printf ("(%dx^%dy^%d) + ",a[i],a[i+1],a[i+2]);
}
printf (" 0 \n");
printf ("How many terms you want to add in the 2nd polynomial ?? : ");
scanf ("%d",&m);
printf ("Enter 2nd polynomial : \n");
for (i=0;i<m*3;i=i+3)
{
printf ("Enter coefficient : ");
scanf("%d",&b[i]);
printf ("Enter power of x : ");
scanf("%d",&b[i+1]);
printf ("Enter power of y : ");
scanf("%d",&b[i+2]);
}
printf ("2nd polynomial is : ");
for (i=0;i<m*3;i=i+3)
{
printf ("(%dx^%dy^%d) + ",b[i],b[i+1],b[i+2]);
}
printf (" 0\n");
printf ("Enter 1 to add : ");
scanf("%d",&z);
switch (z)
{
case 1:
for (i=0;i<n*3;i++)
{c[i]=a[i];}
for (i=n*3,j=0;i<(n+m)*3,j<m*3;i++,j++)
{c[i]=b[j];}
for (i=0;i<(m+n)*3;i=i+3)
{
printf ("(%dx^%dy^%d) + ",c[i],c[i+1],c[i+2]);
}
printf (" 0\n");
}
for (i=1;i<(m+n)*3;i=i+3)
{
for (j=4;j<(m+n)*3;j=j+3)
{
if (c[i]==c[j])
{ if(c[i+1]==c[j+1])
{
c[i-1]=c[i-1]+c[j-1];
c[j-1]=0;
}
}
}
}
printf ("ADDITION \n");
for (i=0;i<(m+n)*3;i=i+3)
if (c[i]!=0)
{
printf ("(%dx^%dy^%d) + ",c[i],c[i+1],c[i+2]);
}
else
printf (" ");
printf (" 0 \n");
}