多项式c语言编程

#include "stdlib.h" #include "stdio.h" typedef struct node{ double coef; //系数 int exp; //指数 struct node *next; }Polynode,*Polynomial; void error(char *s){ fprintf(stderr,"%s\n",s); exit(1); } Polynode* createNode(double coef,int exp){ // 为结点分配空间 Polynode *p=(Polynode*)malloc(sizeof(Polynode)); if(!p) error("分配失败"); p->coef=coef; p->exp=exp; p->next=NULL; return p; } void insertNode(Polynomial p,Polynode *newnode){ Polynode *q=p; //找到链的末尾,循环结束时,p指向最后一个结点while(q->next!=NULL) q=q->next; q->next=newnode; } Polynomial createPolynomial(int m){ double coef; int exp,i=1; Polynode *newnode; Polynomial p; // 创建头结点 newnode=createNode(0,0); // p指向头结点 p=newnode; // 依次创建多项式各项对应的结点 while(i<=m){ printf("系数=");scanf("%lf",&coef); printf("指数=");scanf("%d",&exp); newnode=createNode(coef,exp); insertNode(p,newnode); i=i+1; } return p; } void append(Polynomial p,Polynode *currentnode){ Polynode *newnode,*q; // 找到链表p的尾结点q q=p; while(q->next) q=q->next; // 复制currentnode指向的每一个结点,链入p的末尾 while(currentnode){ newnode=createNode(currentnode->coef,currentnode->exp); q->next=newnode; q=q->next; currentnode=currentnode->next; } } void outputPolynomial(Polynomial p){ Polynode *currentnode; currentnode=p->next; if(!currentnode) error("Polynomial is null"); // 输出第一项 printf("%lfx^%d",currentnode->coef,currentnode->exp); currentnode=currentnode->next; while(currentnode){ if(currentnode->coef>0) printf("+"); printf("%lfx^%d",currentnode->coef,currentnode->exp); currentnode=currentnode->next; } printf("\n"); } void freePolynomial(Polynomial p){ Polynode *q; while(p){ q=p;p=p->next; free(q); } } Polynomial addPolynomial(Polynomial pa,Polynomial pb){ Polynomial pc; Polynode *currenta,*currentb,*newnode; double coef; currenta=pa->next; currentb=pb->next; newnode=createNode(0,0); // 创建链表pc的头结点 pc=newnode; //pc指向头结点while(currenta&¤tb){ if(currenta->exp>currentb->exp){ newnode=createNode(currentb->coef,currentb->exp); insertNode(pc,newnode); currentb=currentb->next; }else if(currenta->expexp){ newnode=createNode(currenta->coef,currenta->exp); insertNode(pc,newnode); currenta=currenta->next; }else{ // 代表currenta->exp==currentb->exp coef=currenta->coef+currentb->coef; if(coef!=0){ newnode=createNode(coef,currenta->exp); insertNode(pc,newnode); } currenta=currenta->next;currentb=currentb->next; } } // 将pa中剩余的节点加入pc中 if(currenta) append(pc,currenta); // 将pb中剩余的节点加入pc中 if(currentb) append(pc,currentb); return pc; } void derivate(Polynomial p){ Polynode *currentnode=p->next; while(currentnode){ currentnode->coef=currentnode->coef*currentnode->exp; currentnode->exp=currentnode->exp-1; currentnode=currentnode->next; } } void showMenu(){ printf("--------------------------\n"); printf(" 1.求和\n"); printf(" 2.求导\n"); printf(" 3.退出\n"); printf("--------------------------\n"); printf("请输入要进行的操作[1或2或3]:"); } void main() { Polynomial pa,pb,pc; int choice,num; while(true){ showMenu(); scanf("%d",&choice); printf("\n"); switch(choice){ // 求和 case 1: printf("请输入多项式1的项数:"); scanf("%d",&num); printf("按照指数从小到大的次序,输入多项式1的系数和指数\n"); pa=createPolynomial(num); printf("请输入多项式2的项数:"); scanf("%d",&num); printf("按照指数从小到大的次序,输入多项式2的系数和指数\n"); pb=createPolynomial(num); pc=addPolynomial(pa,pb); printf("多项式1:"); outputPolynomial(pa); printf("多项式2:"); outputPolynomial(pb); printf("求和的结果:"); outputPolynomial(pc); // 释放空间 freePolynomial(pa); freePolynomial(pb); freePolynomial(pc); break; // 求导 case 2: printf("请输入多项式的项数:"); scanf("%d",&num); printf("按照指数从小到大的次序,输入多项式的系数和指数\n"); pc=createPolynomial(num); printf("输入的多项式:"); outputPolynomial(pc); derivate(pc); printf("求导的结果:"); outputPolynomial(pc); freePolynomial(pc); break; // 退出 case 3: exit(0); // 错误的输入 default: printf("输入错误\n"); exit(0); } } }