multiply.h

实现了任意长度整数的加减乘除以及成n次方运算

#include<stdio.h>
#include "ADD.h"

/*
void Multiply(struct head *oprnd1, struct head *oprnd2, struct head *result)
{
	struct node *n1, *n2, *rslt, *forshift;
	struct head *headnode;
	
	CreatandStore(result, 0);
	n1 = oprnd1->left;
	n2 = oprnd2->left;
	headnode = new struct head;
	for(int i=0; n2 != NULL; i++)
	{

		long m11, m12, m21, m22, r1, r2;	
		long ovrflwdgt1 = 0, ovrflwdgt2 = 0;
		
		for(int j=0; n1 != NULL; j++)
		{
			// divide the 8 digits into two 4 digits to multiply
			MakeNull(headnode);
											
			m11 = n1->data/10000;
			m12 = n1->data%10000;
			m21 = n2->data/10000;
			m22 = n2->data%10000;

			r1 = m22 * m12;
			r2 = m22 * m11 + m21 * m12 ;
			ovrflwdgt1 = Over_flow4(r2);
			r2 = r2 - ovrflwdgt1 * 10000;
			r1 = r1 + r2 * 10000; 
			ovrflwdgt2 = Over_flow(r1);
			r1 = r1 - ovrflwdgt2 * 100000000;
			ovrflwdgt2 = m21 * m11 + ovrflwdgt1 + ovrflwdgt2;
			rslt = new struct node;
			rslt->data = r1;
			
			InsertLeft(headnode, rslt);
				
			if(ovrflwdgt2 != 0)
			{
				rslt = new struct node;
				rslt->data = ovrflwdgt2;
				InsertLeft(headnode, rslt);
			}

			// shift and add

			for(int x=0; x<i+j; x++)
			{
				forshift = new struct node;
				forshift->data = 0;
				InsertRight(headnode, forshift);
			}
			OutPutData(headnode);
			OutPutData(result);
			result = BasicAdd(result, headnode);
			OutPutData(result);

			n1 = NextLeft(n1);
		}
		n2 = NextLeft(n2);
		n1 = FirstLeft(oprnd1);
	}

	//set the sign of Multiply result
	if(Sign(oprnd1) == Sign(oprnd2))
	{
		Assign(result, true);
	}
	else
	{
		Assign(result, false);
	}

	SetNoofDigits(result);	
	SetNoofNode(result);
	OutPutData(result);
}


struct head *Multiply(struct head *headnode1, struct head *headnode2)
{
	struct head *headnode3 = new struct head;
	Multiply(headnode1, headnode2, headnode3);
	return headnode3;
}
*/

struct head *Multiply(struct head *oprnd1, struct head *oprnd2)
{
	struct node *n1, *n2, *rslt, *forshift;
	struct head *result = new struct head;
	struct head *headnode;
	
	CreatandStore(result, 0);
	n1 = oprnd1->left;
	n2 = oprnd2->left;
	headnode = new struct head;
	for(int i=0; n2 != NULL; i++)
	{

		long m11, m12, m21, m22, r1, r2;	
		long ovrflwdgt1 = 0, ovrflwdgt2 = 0;
		
		for(int j=0; n1 != NULL; j++)
		{
			// divide the 8 digits into two 4 digits to multiply
			MakeNull(headnode);
											
			m11 = n1->data/10000;
			m12 = n1->data%10000;
			m21 = n2->data/10000;
			m22 = n2->data%10000;

			r1 = m22 * m12;
			r2 = m22 * m11 + m21 * m12 ;
			ovrflwdgt1 = Over_flow4(r2);
			r2 = r2 - ovrflwdgt1 * 10000;
			r1 = r1 + r2 * 10000; 
			ovrflwdgt2 = Over_flow(r1);
			r1 = r1 - ovrflwdgt2 * 100000000;
			ovrflwdgt2 = m21 * m11 + ovrflwdgt1 + ovrflwdgt2;
			rslt = new struct node;
			rslt->data = r1;
			
			InsertLeft(headnode, rslt);
				
			if(ovrflwdgt2 != 0)
			{
				rslt = new struct node;
				rslt->data = ovrflwdgt2;
				InsertLeft(headnode, rslt);
			}

			// shift and add

			for(int x=0; x<i+j; x++)
			{
				forshift = new struct node;
				forshift->data = 0;
				InsertRight(headnode, forshift);
			}

			result = BasicAdd(result, headnode);


			n1 = NextLeft(n1);
		}
		n2 = NextLeft(n2);
		n1 = FirstLeft(oprnd1);
	}

	//set the sign of Multiply result
	if(Sign(oprnd1) == Sign(oprnd2))
	{
		Assign(result, true);
	}
	else
	{
		Assign(result, false);
	}

	SetNoofDigits(result);	
	SetNoofNode(result);
    return result;
}