Implementation of Polynomial operations in C ++

# Include "Define. H"

Typedef struct
{
Float coef; // Coefficient
Int EXPN; // Index
} Term, elemtype;
Typedef struct lnode
{
Elemtype data;
Struct lnode * next;
} * Link;
Typedef struct
{
Link head, tail;
Int Len;
} Linklist;

Typedef linklist polynomial;

Status makenode (link & P, elemtype E)
{
// Assign a node with the value pointed to by P to E.
P = (Link) malloc (sizeof (lnode ));
If (P)
{
P-> data. coef = E. coef;
P-> data. EXPN = E. EXPN;
P-> next = NULL;
Return OK;
}
Else
Return 0;
}

Link gethead (linklist L)
{
Return L. head;
}

Status setcurelem (link & P, elemtype E)
{
// Use e to update the node specified by P
If (! P)
{
Printf ("P is null! ");
Return Error;
}
P-> data. coef = E. coef;
P-> data. EXPN = E. EXPN;
Return OK;
}

Link locateelem (linklist L, elemtype E, status (* compare) (elemtype, elemtype ))
{
// Return the first position in the linear linked list that matches the compare () determination relationship with E. If no value exists, null is returned.
Link P;
P = L. Head-> next;
While (P! = NULL &&! (* Compare) (p-> data, e ))
P = p-> next;
If (P! = NULL)
Return P;
Else
Return NULL;
}

Status initlist (linklist & L)
{
L. Head = L. Tail = (Link) malloc (sizeof (lnode ));
If (! L. Head)
Exit (-2 );
L. Len = 0; // The length is not the header node.
L. Head-> next = NULL;
Return OK;
}

Status ecqual (elemtype A, elemtype B)
{
If (A. EXPN = B. EXPN)
Return OK;
Return Error;
}

Void insfirst (link H, link S)
{
// Insert a node (header)
S-> next = H-> next;
H-> next = s;
}

Void getcurelem (link P, elemtype &)
{
// Assign the value of P to
A. coef = p-> data. coef;
A. EXPN = p-> data. EXPN;
}

Link nextpos (linklist L, link P)
{
If (! P-> next)
// Cout <"the end! "<Endl;
Return NULL;
Return p-> next;
}

Status CMP (elemtype A, elemtype B)
{
If (A. EXPN> B. EXPN)
Return 1;
Else if (A. EXPN = B. EXPN)
Return 0;
Else
Return-1;
}

Status listempty (linklist L)
{
// Null, return true
If (L. Head-> next = NULL)
Return true;
Else
Return false;
}

Status delfirst (link H, link & P)
{
// Delete the first node in the table and return it as P
If (H-> next = NULL)
{
Cout <"this is empty! "<Endl;
P = H-> next;
Return 0;
}
P = H-> next;
H-> next = p-> next;
P-> next = NULL;
Return OK;
}

Void freenode (link & P)
{
Free (P );
}

Status clearlist (linklist & L)
{
Link P, h;
H = L. head;
P = H-> next;
While (P! = NULL)
{
H = p-> next;
Freenode (P );
P = h;
}
 
If (! P)
{
L. Head-> next = NULL;
L. Tail = L. head;
L. Len = 0;
Return OK;
}
Else
Return Error;
}

Void append (linklist & L, link S)
{
// Link a string of nodes referred to by S to the end of the L table
Int I = 0;
While (L. Tail-> next)
{
L. Tail = L. Tail-> next;
}
L. Tail-> next = s;
While (L. Tail-> next)
{
L. Tail = L. Tail-> next;
I ++;
}
L. Len + = I;
}

Void destroypolyn (Polynomial & P)
{
// Destroy Polynomials
If (P. Head)
{
Freenode (P. Head );
P. Head = P. Head-> next;
}
}

Void printpolyn (polynomial P)
{
// Print
Link h;
H = gethead (P );
H = H-> next;
If (H-> data. EXPN = 0)
Printf ("% F", H-> data. coef );
Printf ("% FX ^ % d", H-> data. coef, H-> data. EXPN );
H = H-> next;
While (h)
{
If (H-> data. EXPN = 0)
Printf ("% F", H-> data. coef );
Else
{
If (H-> data. coef> 0)
Printf ("+ ");
Printf ("% FX ^ % d", H-> data. coef, H-> data. EXPN );
}
H = H-> next;
}
Printf ("/N ");
}

Int polynlength (polynomial P)
{
// Returns the number of polynomials.
Int I;
I = 0;
While (P. Head)
{
I ++;
P. Head = P. Head-> next;
}
Return I;
}

Void createpolyn (Polynomial & P, int m)
{
// Input the index and coefficient of M, and establish an ordered linked list p that represents a polynomial.
Link H, S;
Term E;
Int I;
Initlist (P );
H = gethead (P );
E. coef = 0.0;
E. EXPN =-1; // set the header Node
Setcurelem (H, e );
// Cout Cout <"Please input coef and EXPN" <"(" <m <", descending)" <":" <Endl;
For (I = 1; I <= m; I ++)
{
// CIN> E. coef> E. EXPN;
Scanf ("% F", & E. coef );
Scanf ("% d", & E. EXPN );
If (! Locateelem (p, E, ecqual ))
If (makenode (S, e ))
Insfirst (H, S );
}
}

Void addpolyn (Polynomial & PA, Polynomial & Pb, status (* CMP) (elemtype, elemtype ))
{
Link ha, Hb, QA, QB;
Elemtype A, B;
// Int T;
Float sum;
Ha = gethead (PA );
HB = gethead (PB );
QA = nextpos (Pa, ha );
QB = nextpos (Pb, Hb );
While (QA & QB)
{
Getcurelem (QA, );
Getcurelem (QB, B );
// T = (* CMP) (A, B );
Switch (* CMP) (a, B ))
{
Case-1: // the current node value in polynomial PA is small.
Ha = QA;
QA = nextpos (Pa, QA );
Break;
Case 0:
Sum = A. coef + B. coef;
If (sum! = 0)
{
QA-> data. coef = sum; // modify the Coefficient
Ha = QA;
}
Else
{
Delfirst (HA, QA );
Freenode (QA );
}
Delfirst (Hb, QB );
Freenode (QB );
QB = nextpos (Pb, Hb );
QA = nextpos (Pa, ha );
Break;
Case 1:
Delfirst (Hb, QB );
Insfirst (HA, QB );
QB = nextpos (Pb, Hb );
Ha = nextpos (Pa, ha );
Break;
}
}
If (! Listempty (PB ))
Append (Pa, QB );
Freenode (HB );
}

Void subtractpolyn (Polynomial & PA, Polynomial & Pb)
{
// Polynomial subtraction and destruction of Pb
Link ha, Hb, QA, QB;
Elemtype A, B;
Float sub;
Ha = gethead (PA );
HB = gethead (PB );
QA = nextpos (Pa, ha );
QB = nextpos (Pb, Hb );
While (QA & QB)
{
Getcurelem (QA, );
Getcurelem (QB, B );
Switch (* CMP) (a, B ))
{
Case-1:
Ha = QA;
QA = nextpos (Pa, QA );
Break;
Case 0:
Sub = A. coef-b.coef;
If (sub! = 0.0)
{
QA-> data. coef = sub;
Ha = QA;
}
Else
{
Delfirst (HA, QA );
Freenode (QA );
}
Delfirst (Hb, QB );
Freenode (QB );
QB = nextpos (Pb, Hb );
QA = nextpos (Pa, ha );
Break;

Case 1:
Delfirst (Hb, QB );
QB-> data. coef * =-1;
Insfirst (HA, QB );
QB = nextpos (Pb, Hb );
Ha = nextpos (Pa, ha );
Break;
}
}
If (! Listempty (PB ))
Append (Pa, QB );
Freenode (HB );
}

/* Void contrary (Polynomial & Q)
{
// Reverse Order
Link P, C, N;
P = NULL; // previous Node
C = Q. Head; // current node
N = Q. Head-> next; // next node
While (n) {// if it does not reach the end of the linked list
C-> next = P; // the current node in reverse order
P = C; // forward the node
C = N; // forward the node
N = N-> next; // node forward
}
C-> next = P;
Q. Head = C;
}*/

Void multiplypolyn (Polynomial & PA, Polynomial & Pb)
{
// Polynomial Multiplication
Polynomial sum, T; // sum saves the addition result, and t saves the result of multiplication in each step.
Link HS, HT, ha, Hb, QA, QB, S, T;
Term E;
// Elemtype A, B;
// Int m, n
/* Int la, Lb;
La = polynlength (PA );
Lb = polynlength (PB );*/
Initlist (SUM );
Initlist (t );
Cout <1 <Endl;
E. coef = 0.0;
E. EXPN =-1; // set the header Node
Ht = gethead (t );
HS = gethead (SUM );
Setcurelem (HS, e );
Setcurelem (HT, e );
Ha = gethead (PA );
If (Ha-> next = NULL)
Cout <"re" <Endl;
QA = nextpos (Pa, ha );
Cout <2 <Endl;
HB = gethead (PB );
While (QA)
{
QB = nextpos (Pb, Hb );
Cout <3 <Endl;
While (QB)
{

E. coef = QA-> data. coef * QB-> data. coef;
E. EXPN = QA-> data. EXPN + QB-> data. EXPN;
If (makenode (S, e ))
{
If (HT-> next = NULL)
{
Ht-> next = s;
T = s;
}
Else
{
T-> next = s;
S-> next = NULL;
T = s;
}
}
QB = QB-> next;
}
QA = QA-> next;
Addpolyn (sum, T, CMP );
Printpolyn (SUM );
Initlist (t );
Ht = gethead (t );
Cout <4 <Endl;
}
Destroypolyn (PB );
HS = gethead (SUM );
HS = nextpos (sum, HS );
Clearlist (PA );
Append (Pa, HS );
}

Void main ()
{
Polynomial A, B;
Createpolyn (A, 2 );
Createpolyn (B, 2 );
Printpolyn ();
Printpolyn (B );
// Addpolyn (a, B, CMP );
// Multiplypolyn (A, B );
Subtractpolyn (A, B );
Printpolyn ();
}