C语言：用链表实现一元多项式的加法

╰+哭是因爲堅強的太久メ 2022-08-03 05:17 173阅读 0赞

/*
    	一元多多项式的加法
    	1.先创建链表，存储多项式
    	2.输出多项式
    	3.两个多项式相加
    	4.输出多项式
    */
    
    # include <stdio.h>
    # include <malloc.h>
    
    typedef struct dxs  //多项式节点
    {
    	float coe;  //系数
    	int exp;   //指数
    	struct dxs * pNext;  //指针域
    
    }DXS, * PDXS;
    
    PDXS creat_dxs();   //创建多项式
    void traverse(PDXS pHead);   //遍历多项式链表
    PDXS add(PDXS Da, PDXS Db);  //多项式求和
    
    int main(void)
    {
    	//用链表结构，创建两个多项式
    	PDXS Da = creat_dxs();
        traverse(Da);
    
    	PDXS Db = creat_dxs();
        traverse(Db);
    
    	//求两个多项式的加法
    	PDXS Dj = add(Da, Db);
    	traverse(Dj);
    
    	return 0;
    }
    
    PDXS creat_dxs()
    {
    	PDXS pHead = (PDXS)malloc(sizeof(DXS)); //创建头结点
    	pHead->pNext = NULL;  //尾指针
    
    	PDXS pTail = pHead;
    	PDXS pNew = NULL;
    
    	int len;
    	float c;
    	int e;
    	int i;
    
    	printf("输入多项式的项数：len = ");
    	scanf("%d", &len);
    
    	for(i = 0; i < len; i++)
    	{
    		printf("分别输入第%d项的系数c、指数e:", i+1);
    		scanf("%f%d", &c, &e);
    		
    		pNew = (PDXS)malloc(sizeof(DXS));
    
    		//多项式项，系数、指数
    		pNew->coe = c;
    		pNew->exp = e;
    		pNew->pNext = NULL;
    
    		pTail->pNext = pNew;
    		pTail = pNew;
    	}
    
    	return pHead;
    }
    
    //遍历链表
    void traverse(PDXS pHead)
    {
    	PDXS p = pHead->pNext;  //首节点
    
    	while(p != NULL)
    	{
    		printf("(%.2f %d), ", p->coe, p->exp);
    		p = p->pNext;
    	}
    	printf("\n");
    }
    
    
    //多项式相加
    PDXS add(PDXS Da, PDXS Db)
    {
    	PDXS Dj = (PDXS)malloc(sizeof(DXS));  //和的头结点
    	Dj->pNext = NULL;
    	PDXS pTail = Dj;  //和的尾节点
    
    	PDXS Dah = Da->pNext;  //指向多项式的首节点
    	PDXS Dbh = Db->pNext;
    
    	//循环遍历多项式A，B
    	while(Dah && Dbh)
    	{
    		//比较当前两节点的指数
    		//当前 A项节点指数 < B项节点指数
    		if(Dah->exp < Dbh->exp)
    		{
    			pTail->pNext = Dah;  //将此A项加入和链表中
    			pTail = Dah;
    
    			Dah = Dah->pNext;  //A多项式向后遍历
    		}
    
    		//当前 A项节点指数 < B项节点指数
    		else if(Dah->exp > Dbh->exp)
    		{
    			pTail->pNext = Dbh;  //将此B项加入和链表中
    			pTail = Dbh;
    
    			Dbh = Dbh->pNext;  // //B多项式向后遍历
    		}
    
    		//如果两节点的指数相等
    		else
    		{
    			//当前指数的系数和不为0
    			//A项中保存系数和，把此A项加入和链表中
    			if(0 != (Dah->coe + Dbh->coe))
    			{
    				Dah->coe = Dah->coe + Dbh->coe;
    				pTail->pNext = Dah;
    				pTail = Dah;		
    			}
    		
    			//A,B都向后遍历
    			Dah = Dah->pNext;
    			Dbh = Dbh->pNext;			
    		}
    	}
    
    	//插入剩余段
    	if(Dah != NULL)
    	{
    		pTail->pNext = Dah;
    	}
    	if(Dbh != NULL)
    	{
    		pTail->pNext = Dbh;
    	}
    
    	return Dj;
    }

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