多项式的链式写法

 

#include<stdio.h>//一元稀疏多项式的计算
#include<iostream>
#include<stdlib.h>
using namespace std;
typedef struct PolyNode  // 结构体
{
    float coef;  //系数
    int exp;     //指数
    struct PolyNode * next;
}PolyNode;
typedef PolyNode * Polynomial;   // 类型声明
Polynomial  CreateList(int n)    //建表并输入
{
    Polynomial L,p,r;
    r = L = (Polynomial )malloc(sizeof(PolyNode ));   //头节点是L不能移动
    L->next = NULL;
    float x;
    int y;
    while(n--)   //判断输入结束的条件为( x!=0 && y!=0 )
    {
    	scanf("%f %d",&x,&y);
        p = (Polynomial )malloc(sizeof(PolyNode ));
        p->coef = x;
        p->exp = y;
        p->next = NULL;
        r->next = p;
        r = p;
    }
    return L;  // 返回输入的链表
}
Polynomial Add(Polynomial A, Polynomial B)  //加法
{
    Polynomial C,S;
    Polynomial pa,pb,pc;
    float x;
    pa = A->next;
    pb = B->next;
    C = (Polynomial )malloc(sizeof(PolyNode ));  // 申请头节点
    pc = C;   // 操作时使用pc指针
    pc->next = NULL;
    while (pa && pb)
    {
        if(pa->exp == pb->exp)  // 指数相等时
        {
            x = pa->coef + pb->coef;
            if (x)     // 相加完的系数不为0时
            {
                S = (Polynomial )malloc(sizeof(PolyNode ));
                S->coef = x;
                S->exp = pa->exp;
                S->next = NULL;
                pc->next = S;
                pc = S;
            }
            pa = pa->next;
            pb = pb->next;
        }
        else
            if(pa->exp < pb->exp)   //指数不相等且A项指数小于B项指数时
            {
                S = (Polynomial )malloc(sizeof(PolyNode ));
                S->coef = pa->coef;
                S->exp = pa->exp;
                S->next = NULL;
                pc->next = S;
                pc = S;
                pa = pa->next;
            }
            else   //指数不相等且A项指数大于B项指数时
            {
                S = (Polynomial )malloc(sizeof(PolyNode ));
                S->coef = pb->coef;
                S->exp = pb->exp;
                S->next = NULL;
                pc->next = S;
                pc = S;
                pb = pb->next;
            }
    }
    while (pa)   //A链表后几项多出来时
    {
        S = (Polynomial )malloc(sizeof(PolyNode ));
        S->coef = pa->coef;
        S->exp = pa->exp;
        S->next = NULL;
        pc->next = S;
        pc = S;
        pa = pa->next;
    }
    while (pb)   //B链表后几项多出来时
    {
        S = (Polynomial )malloc(sizeof(PolyNode ));
        S->coef = pb->coef;
        S->exp = pb->exp;
        S->next = NULL;
        pc->next = S;
        pc = S;
        pb = pb->next;
    }
    return C;
}
Polynomial Minus(Polynomial A, Polynomial B)  //减法，判断条件等都同上
{
    Polynomial C,S;
    Polynomial pa,pb,pc;
    float x;
    pa = A->next;
    pb = B->next;
    C = (Polynomial )malloc(sizeof(PolyNode ));
    pc = C;
    pc->next = NULL;
    while (pa && pb)
    {
        if(pa->exp == pb->exp)
        {
            x = pa->coef - pb->coef; //系数相减
//            if (x)
//            {
                S = (Polynomial )malloc(sizeof(PolyNode ));
                S->coef = x;
                S->exp = pa->exp;
                S->next = NULL;
                pc->next = S;
                pc = S;
//            }
            pa = pa->next;
            pb = pb->next;
        }
        else
            if(pa->exp < pb->exp)
            {
                S = (Polynomial )malloc(sizeof(PolyNode ));
                S->coef = pa->coef;
                S->exp = pa->exp;
                S->next = NULL;
                pc->next = S;
                pc = S;
                pa = pa->next;
            }
            else
            {
                S = (Polynomial )malloc(sizeof(PolyNode ));
                S->coef = -pb->coef;  // Pb放上去时，需要为负 
                S->exp = pb->exp;
                S->next = NULL;
                pc->next = S;
                pc = S;
                pb = pb->next;
            }
    }
    while (pa)
    {
        S = (Polynomial )malloc(sizeof(PolyNode ));
        S->coef = pa->coef;
        S->exp = pa->exp;
        S->next = NULL;
        pc->next = S;
        pc = S;
        pa = pa->next;
    }
    while (pb)
    {
        S = (Polynomial )malloc(sizeof(PolyNode ));
        S->coef = -pb->coef; // Pb放上去时，需要为负 
        S->exp = pb->exp;
        S->next = NULL;
        pc->next = S;
        pc = S;
        pb = pb->next;
    }
    return C;
}
void PrintfPolyn(Polynomial P){//输出多项式
    Polynomial t;
    t=P->next;
    if(t==NULL)
    {
        cout<<"0"<<endl;
        return;
    }
    while(t->next){
//        if(t->exp!=0)
//        {
//            if(t->coef!=1&&t->coef!=-1)
            cout<<t->coef<<"X";
//            else if(t->coef==1)
//                cout<<"X";
//            else
//                cout<<"-X";
            if(t->next->coef>=0)
                cout<<"^"<<t->exp<<"+";
            else
                cout<<"^"<<t->exp;
//        }
//        else
//            cout<<t->coef;
        t=t->next;
    }
//    if(t->exp!=0){
////        if(t->coef!=1&&t->coef!=-1)
//          cout<<t->coef<<"X";
////        else if(t->coef==1)
////            cout<<"x";
////        else
////            cout<<"-x";
//        if(t->exp!=1)
//            cout<<"^"<<t->exp;
//    }
//    else
//        cout<<t->coef;
	cout << t->coef << "X^" <<t->exp;
    cout<<endl;
}
int main()
{ 
    Polynomial  P1,P2;
    int t;
	cin >> t;
	while(t--){
		int n, m; 
		cin >> n >> m;
		P1 = CreateList(n);
		P2 = CreateList(m);
		int T;
		cin >> T;
		while(T--){
			int type;
			cin >> type;
			if(type == 1){
				// 输出
				PrintfPolyn(P1);
				PrintfPolyn(P2);
			}
			else if (type == 2){
				// 相加到第一个
				P1 = Add(P1,P2);
			}
			else if (type == 3){
				// 相减到第一个
				P1 =  Minus(P1, P2);
			}
	    }
    }
    return 0;
}

/*
1
2 3
2 0 0 4
4 5 5 6 6 7
5
1
3
1
2
1
https://blog.csdn.net/chuck_0430/article/details/8184846
*/