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兩個多項式相加及相乘

#include <stdio.h>
#include <malloc.h> 

 typedef struct PolyNode *Polynomial;
 struct PolyNode{
    int coef;
    int expon;
    Polynomial link;
 };

 void Attach(int c,int e,Polynomial *pRear) //pRear是指標的指標 
 {
    Polynomial P;

    P=(Polynomial)malloc(sizeof(struct PolyNode));
    P->
coef=c; //對新結點賦值 P->expon=e; P->link=NULL; (*pRear)->link=P; //修改pRear的值 *pRear=P; } Polynomial ReadPoly() { Polynomial P,Rear,t; int c,e,N; scanf("%d",&N); P=(Polynomial)malloc(sizeof(struct PolyNode)); //連結串列頭空結點 P->link=NULL; Rear=P; while
(N--){ scanf("%d%d",&c,&e); Attach(c,e,&Rear); //將當前項插入多項式尾部 } t=P;P=P->link;free(t); //刪除臨時生成的頭結點 return P; } Polynomial Add(Polynomial P1,Polynomial P2) { Polynomial front,rear,temp; int sum; rear=(Polynomial)malloc(sizeof(struct PolyNode)); front=
rear; /*由front記錄結果多項式連結串列頭結點*/ while(P1&&P2){ /*當兩個多項式都有非零項待處理時*/ if(P1->expon==P2->expon){ sum=P1->coef+P2->coef; if(sum){ Attach(sum,P1->expon,&rear); P1=P1->link; P2=P2->link; }else{ P1=P1->link; P2=P2->link; } }else if(P1->expon>P2->expon){ Attach(P1->coef,P1->expon,&rear); P1=P1->link; }else{ Attach(P2->coef,P2->expon,&rear); P2=P2->link; } } /*將未處理完的另一個多項式的所有節點依次複製到結果多項式中去*/ while(P1){ Attach(P1->coef,P1->expon,&rear); P1=P1->link; } while(P2){ Attach(P2->coef,P2->expon,&rear); P2=P2->link; } rear->link=NULL; temp=front; front=front->link; /*令front指向結果多項式第一個非零項*/ free(temp); /*釋放臨時空表頭結點*/ return front; } /*採用逐項插入的方法,將P1當前項乘以P2的當前項,並插入到結果多項式中,關鍵是要找到插入的位置*/ /*初始結果多項式由P1第一項乘以P2各項獲得*/ Polynomial Mult(Polynomial P1,Polynomial P2) { Polynomial P,Rear,t1,t2,t; int c,e; if(!P1||!P2){ return NULL; } t1=P1;t2=P2; P=(Polynomial)malloc(sizeof(struct PolyNode));P->link=NULL; Rear=P; while(t2){ //P1第一項乘以P2各項得到初始結果多項式 Attach(t1->coef*t2->coef,t1->expon+t2->expon,&Rear); t2=t2->link; } t1=t1->link; while(t1){ t2=P2;Rear=P; while(t2){ e=t1->expon+t2->expon; c=t1->coef*t2->coef; while(Rear->link&&Rear->link->expon>e) Rear=Rear->link; if(Rear->link&&Rear->link->expon==e){ if(Rear->link->coef+c) Rear->link->coef+=c; else{ t=Rear->link; Rear->link=t->link; free(t); } } else{ t=(Polynomial)malloc(sizeof(struct PolyNode)); t->coef=c; t->expon=e; t->link=Rear->link; Rear->link=t; Rear=Rear->link; } t2=t2->link; //printf("%d,%d\n",Rear->coef,Rear->expon); } t1=t1->link; } t2=P;P=P->link;free(t2); return P; } void PrintPoly(Polynomial P) { int flag=0; //輔助調整輸出格式用 if(!P){ printf("0 0\n"); return; } while(P){ if(!flag) flag=1; else printf(" "); printf("%d %d",P->coef,P->expon); P=P->link; } } int main() { Polynomial P1,P2,PS,PP; P1=ReadPoly(); P2=ReadPoly(); PP=Mult(P1,P2); PrintPoly(PP); printf("\n"); PS=Add(P1,P2); PrintPoly(PS); return 0; } /* 測試資料 4 3 5 2 4 3 3 6 1 3 2 5 3 4 4 3 */