Polynomial Equation

#include<stdio.h>
#include<conio.h>

struct poly
{
 int coef;
 int xexp;
 int yexp;
 int zexp;
 struct poly *link;
}*ply1,*ply2,*sply,*rear,*nw,*ptr,*locp,*loc,*loca;

int cho;

void ins_poly()
{
 //cho = 0;
 do
 {
 nw = new poly;
 printf("\n Enter the coefficient : ");
 scanf("%d",&nw->coef);
 printf("\n Enter the power for 'x' : ");
 scanf("%d",&nw->xexp);
 printf("\n Enter the power for 'y' : ");
 scanf("%d",&nw->yexp);
 printf("\n Enter the power for 'z' : ");
 scanf("%d",&nw->zexp);
 nw->link = NULL;
 if(ply1 == NULL)
   ply1 = nw;
 else
 {
  locp = NULL;
  loc = ply1;
  while(loc != NULL && ( nw->xexp < loc->xexp || (nw->xexp == loc->xexp && nw->yexp < loc->yexp ) || (nw->xexp == loc->xexp && nw->yexp == loc->yexp && nw->zexp < loc->zexp )) )
  {
   locp = loc; loc = loc->link;
  }
  if(nw->xexp == loc->xexp && nw->yexp == loc->yexp && nw->zexp == loc->zexp )
  {
   loc->coef += nw->coef;
   delete nw;
  }
  else
  {
  if(locp == NULL)
  {
   nw->link = ply1;
   ply1 = nw;
  }
  else
  {
   nw->link = loc;
   locp->link = nw;
  }
 }
 }
 printf("\n\n Enter '1' to continue : ");
 scanf("%d",&cho);
 }while(cho == 1);

 do
 {
 nw = new poly;
 printf("\n Enter the coefficient : ");
 scanf("%d",&nw->coef);
 printf("\n Enter the power for 'x' : ");
 scanf("%d",&nw->xexp);
 printf("\n Enter the power for 'y' : ");
 scanf("%d",&nw->yexp);
 printf("\n Enter the power for 'z' : ");
 scanf("%d",&nw->zexp);
 nw->link = NULL;
 if(ply2 == NULL)
   ply2 = nw;
 else
 {
  locp = NULL;
  loc = ply2;
  while(loc != NULL && ( nw->xexp < loc->xexp || (nw->xexp == loc->xexp && nw->yexp < loc->yexp ) || (nw->xexp == loc->xexp && nw->yexp == loc->yexp && nw->zexp < loc->zexp )) )
  {
   locp = loc; loc = loc->link;
  }
  if(nw->xexp == loc->xexp && nw->yexp == loc->yexp && nw->zexp == loc->zexp )
  {
   loc->coef += nw->coef;
   delete nw;
  }
  else
  {
  if(locp == NULL)
  {
   nw->link = ply2;
   ply2 = nw;
  }
  else
  {
   nw->link = loc;
   locp->link = nw;
  }
  }
 }
 printf("\n\n Enter '1' to continue : ");
 scanf("%d",&cho);
 }while(cho == 1);
}

void add_poly()
{
 loc = ply1;
 loca = ply2;
 sply = NULL;
 while(loc != NULL && loca != NULL)
 {
  nw = new poly;
  if(loc->xexp > loca->xexp || loc->yexp > loca->yexp || loc->zexp > loca->zexp )
  {
   nw = loc;
   loc = loc->link;
  }
  else if(loc->xexp < loca->xexp || loc->yexp < loca->yexp || loc->zexp < loca->zexp )
  {
   nw = loca;
   loca = loca->link;
  }
  else
  {
   nw = loc;
   nw->coef = loca->coef + loc->coef;
   loc = loc ->link;
   loca = loca ->link;
  }
  nw->link = NULL;
  if(sply == NULL)
   sply = rear = nw;
  else
  {
   rear->link = nw;
   rear = nw;
  }
 }
 while(loc != NULL)
 {
  nw = new poly;
  nw = loc;
  rear->link = nw;
  rear = nw;
  loc = loc->link;
 }
 while(loca != NULL)
 {
  nw = new poly;
  nw = loca;
  rear->link = nw;
  rear = nw;
  loca = loca->link;
 }
}

void main()
{
 clrscr();
 ins_poly();
 printf(" (%d)*pow(x,%d)*pow(y,%d)*pow(z,%d)",ply1->coef,ply1->xexp,ply1->yexp,ply1->zexp);
 ptr = ply1->link;
 while(ptr != NULL)
 {
  printf(" + (%d)*pow(x,%d)*pow(y,%d)*pow(z,%d)",ptr->coef,ptr->xexp,ptr->yexp,ptr->zexp);
  ptr = ptr->link;
 }

  printf("\n\n (%d)*pow(x,%d)*pow(y,%d)*pow(z,%d)",ply2->coef,ply2->xexp,ply2->yexp,ply2->zexp);
 ptr = ply2->link;

 while(ptr != NULL)
 {
  printf(" + (%d)*pow(x,%d)*pow(y,%d)*pow(z,%d)",ptr->coef,ptr->xexp,ptr->yexp,ptr->zexp);
  ptr = ptr->link;
 }
 add_poly();

 printf("\n\n\n (%d)*pow(x,%d)*pow(y,%d)*pow(z,%d)",sply->coef,sply->xexp,sply->yexp,sply->zexp);
 ptr = sply->link;
 while(ptr != NULL)
 {
  printf(" + (%d)*pow(x,%d)*pow(y,%d)*pow(z,%d)",ptr->coef,ptr->xexp,ptr->yexp,ptr->zexp);
  ptr = ptr->link;
 }
 getch();
}