02-线性结构1 一元多项式的乘法与加法运算

#include 
#include  

typedef struct node{
	int coefficient;
	int exponent;
	struct node * next;
} PolyNode, *Polynomial;

Polynomial ReadPoly();
void Attach(int c, int e, Polynomial * Rear);
Polynomial MultPoly(Polynomial P1, Polynomial P2);
Polynomial AddPoly(Polynomial P1, Polynomial P2);
void PrintPoly(Polynomial P);

int main(int argc, char const *argv[])
{
	Polynomial Poly1, Poly2, PolySum, PolyMul;

	Poly1 = ReadPoly();
	Poly2 = ReadPoly();
	PolyMul = MultPoly(Poly1, Poly2);
	PrintPoly(PolyMul);
	PolySum = AddPoly(Poly1, Poly2);
	PrintPoly(PolySum);

	return 0;
}

Polynomial ReadPoly()
{
	Polynomial P, Rear, temp;
	P = (PolyNode*)malloc(sizeof(PolyNode));
	P->next = NULL;
	Rear = P;
	int N, c, e;
	scanf("%d", &N);
	while(N--){
		scanf("%d %d", &c, &e);
		Attach(c, e, &Rear);
	}
	temp = P;
	P = P->next; 
	free(temp);
	return P;
}

void Attach(int c, int e, Polynomial * pRear)
{
	Polynomial P;
	P = (PolyNode*)malloc(sizeof(PolyNode));
	P->coefficient = c;
	P->exponent = e;
	P->next = NULL;
	(*pRear)->next = P;
	*pRear = P;
}

Polynomial MultPoly(Polynomial P1, Polynomial P2)
{
	Polynomial P, temp1, temp2, Rear, temp;
	int c, e;
	if(!P1 || !P2)
		return NULL;
	temp1 = P1;
	temp2 = P2;
	P = (PolyNode*)malloc(sizeof(PolyNode));
	P->next = NULL;
	Rear = P;
	while(temp2){
		c = temp1->coefficient * temp2->coefficient;
		e = temp1->exponent + temp2->exponent;
		if(c != 0){
			Attach(c, e, &Rear);
			temp2 = temp2->next;
		}
	}
	temp1 = temp1->next;
	while(temp1){
		temp2 = P2, Rear = P;
		while(temp2){
			c = temp1->coefficient * temp2->coefficient;
			e = temp1->exponent + temp2->exponent;
			if(c != 0){
				while(Rear->next && Rear->next->exponent > e)
					Rear = Rear->next;
				if(Rear->next && Rear->next->exponent == e){
					if(Rear->next->coefficient + c)
						Rear->next->coefficient += c;
					else{
						temp = Rear->next;
						Rear->next = temp->next;
						free(temp);
					}
				}
				else{
					temp = (PolyNode*)malloc(sizeof(PolyNode));
					temp->coefficient = c;
					temp->exponent = e;
					temp->next = Rear->next;
					Rear->next = temp;
					Rear = Rear->next;
				}
				temp2 = temp2->next;
			}
		}
		temp1 = temp1->next;
	}
	temp = P;
	P = P->next;
	free(temp);
	return P;
}

Polynomial AddPoly(Polynomial P1, Polynomial P2)
{
	Polynomial P, temp1, temp2, Rear, temp;
	if(!P1 && !P2){
		if(!P1)
			return P2;
		else
			return P1;
	}
	P = (PolyNode*)malloc(sizeof(PolyNode));
	P->next = NULL;
	Rear = P;
	temp1 = P1;
	temp2 = P2;
	while(temp1 && temp2){
		if(temp1->exponent > temp2->exponent){
			if(temp1->coefficient){
				Attach(temp1->coefficient, temp1->exponent, &Rear);				
			}
			temp1 = temp1->next;
		}
		else if(temp1->exponent == temp2->exponent){
			if(temp1->coefficient + temp2->coefficient){
				Attach(temp1->coefficient + temp2->coefficient, temp1->exponent, &Rear);
			}
			temp1 = temp1->next;
			temp2 = temp2->next;
		}
		else{
			if(temp2->coefficient){
				Attach(temp2->coefficient, temp2->exponent, &Rear);				
			}
			temp2 = temp2->next;
		}
	}
	while(temp1){
		Attach(temp1->coefficient, temp1->exponent, &Rear);
		temp1 = temp1->next;
	}
	while(temp2){
		Attach(temp2->coefficient, temp2->exponent, &Rear);
		temp2 = temp2->next;
	}
	temp = P;
	P = P->next;
	free(temp);
	return P;
}

void PrintPoly(Polynomial P)
{
	int flag = 0;
	if(!P){
		printf("0 0");
	}
	while(P){
		if (!flag)
			flag = 1;
		else
			printf(" ");
		printf("%d %d", P->coefficient, P->exponent);
		P = P->next;
	}
	printf("\n");
}