多项式加法-->动态实现

来源：互联网发布：高中数学知乎编辑：程序博客网时间：2024/06/08 18:22

前面多项式的加法实现使用的是数组进行实现的，这里介绍的使用链表进行实现的，使用链表进行实现更加高效；
对于多项式使用链表来进行实现，首先应该解决的是创建多项式的问题；

void CreatPolynomial(polyPointer *phead, polyNode item){    polyPointer temp = (polyPointer)malloc(sizeof(polyPointer));    if (temp == NULL)    {        fprintf(stderr, "malloc error\n");        exit(EXIT_FAILURE);    }    polyPointer templink = *phead;    temp->coef = item.coef;    temp->expon = item.expon;    temp->link = NULL;    if (*phead == NULL) *phead = temp;    else    {        while (templink->link != NULL) templink = templink->link;        templink->link = temp;    }}

在进行多项式加法运算过程中，需要通过attach函数来连接各个多项式；

void attach(float coefficient, int exponent, polyPointer *ptr){    polyPointer temp;    temp = (polyPointer)malloc(sizeof(polyPointer));    if (temp == NULL)    {        fprintf(stderr, "malloc error.\n");        exit(EXIT_FAILURE);    }    temp->coef = coefficient;    temp->expon = exponent;    (*ptr)->link = temp;    *ptr = temp;}

多项式相加函数，这个函数需要处理的情况包括;
- 系数相加；
- 指数比较；
- 并且需要创建新节点；

polyPointer padd(polyPointer a, polyPointer b){    polyPointer c, rear, temp;    int sum;    rear = (polyPointer)malloc(sizeof(*rear));    if (rear == NULL)    {        fprintf(stderr, "malloc error.\n");        exit(EXIT_FAILURE);    }    c = rear;    while (a && b)        switch (COMPARE(a->expon, b->expon))        {        case -1:            attach(b->coef, b->expon, &rear);            b = b->link;            break;        case 0:            sum = a->coef + b->coef;            if (sum)                attach(sum, b->expon, &rear);            a = a->link;            b = b->link;            break;        case 1:            attach(a->coef, a->expon, &rear);            a = a->link;        }    for (; a; a = a->link) attach(a->coef, a->expon, &rear);    for (; b; b = b->link) attach(b->coef, b->expon, &rear);    rear->link = NULL;    temp = c;    c = c->link;    free(temp);    return c;}

完整的程序过程：

#include<stdio.h>#include<stdlib.h>#define COMPARE(X,Y)  (((X)<(Y)) ? -1:(X)==(Y) ? 0 :1)typedef struct Node *polyPointer;typedef struct Node polyNode;struct Node{    int coef;    int expon;    polyPointer link;};void attach(float coefficient, int exponent, polyPointer *ptr){    polyPointer temp;    temp = (polyPointer)malloc(sizeof(polyPointer));    if (temp == NULL)    {        fprintf(stderr, "malloc error.\n");        exit(EXIT_FAILURE);    }    temp->coef = coefficient;    temp->expon = exponent;    (*ptr)->link = temp;    *ptr = temp;}polyPointer padd(polyPointer a, polyPointer b){    polyPointer c, rear, temp;    int sum;    rear = (polyPointer)malloc(sizeof(*rear));    if (rear == NULL)    {        fprintf(stderr, "malloc error.\n");        exit(EXIT_FAILURE);    }    c = rear;    while (a && b)        switch (COMPARE(a->expon, b->expon))        {        case -1:            attach(b->coef, b->expon, &rear);            b = b->link;            break;        case 0:            sum = a->coef + b->coef;            if (sum)                attach(sum, b->expon, &rear);            a = a->link;            b = b->link;            break;        case 1:            attach(a->coef, a->expon, &rear);            a = a->link;        }    for (; a; a = a->link) attach(a->coef, a->expon, &rear);    for (; b; b = b->link) attach(b->coef, b->expon, &rear);    rear->link = NULL;    temp = c;    c = c->link;    free(temp);    return c;}void CreatPolynomial(polyPointer *phead, polyNode item){    polyPointer temp = (polyPointer)malloc(sizeof(polyPointer));    if (temp == NULL)    {        fprintf(stderr, "malloc error\n");        exit(EXIT_FAILURE);    }    polyPointer templink = *phead;    temp->coef = item.coef;    temp->expon = item.expon;    temp->link = NULL;    if (*phead == NULL) *phead = temp;    else    {        while (templink->link != NULL) templink = templink->link;        templink->link = temp;    }}void polyNodeErase(polyPointer *phead){    polyPointer temp;    while(*phead){        temp=*phead;        *phead=(*phead)->link;        free(temp);    }}void PolynomialPrint(polyPointer phead){    while (phead != NULL)    {        printf("[%d]--[%d]\n", phead->coef, phead->expon);        phead = phead->link;    }}int main(){    polyPointer aphead = NULL;    polyNode item;    item.coef = 10;    item.expon = 3;    CreatPolynomial(&aphead, item);    item.coef = 11;    item.expon = 2;    CreatPolynomial(&aphead, item);    item.coef = 9;    item.expon = 1;    CreatPolynomial(&aphead, item);    printf("a contains:\n");    PolynomialPrint(aphead);    polyPointer bphead = NULL;    polyNode item2;    item2.coef = 22;    item2.expon = 4;    CreatPolynomial(&bphead, item2);    printf("b contains:\n");    PolynomialPrint(bphead);    polyPointer c = padd(aphead, bphead);    printf("the result is:\n");    PolynomialPrint(c);    polyNodeErase(&aphead);    polyNodeErase(&bphead);    polyNodeErase(&c);    return 0;}

程序的执行结果：

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