L1和L2是两个带头结点的单链表表示的多项式，编写算法计算两个多项式的乘积，运算结果仍用单链表进行存储
#include <iostream>using namespace std;typedef struct LNode { int coefficient; //系数 int degree; //次数 struct LNode *next; //下一个结点} LNode, *LinkedList;/** * 查找计算结果应该插入的位置 * @param L 链表的头结点指针 * @param degree 次数 * @return 插入结点的前一个结点 */LinkedList findPre(LinkedList L, int degree) { LinkedList pre = L; LNode *p = L->next; while (p != nullptr) { if (p->degree <= degree) { break; } pre = p; p = p->next; } return pre;}/** * 两个多项式进行乘法运算（多项式的次数按递减排列） * @param L1 多项式一 * @param L2 多项式二 * @return 计算结果 */LinkedList calculate(LinkedList L1, LinkedList L2) { // 结果的头结点 LinkedList head = (LinkedList) malloc(sizeof(LNode)); head->next = nullptr; LNode *p = L1->next; while (p != nullptr) { LNode *q = L2->next; while (q != nullptr) { // 暂存结点信息 LinkedList temp = (LinkedList) malloc(sizeof(LNode)); // 系数相乘 temp->coefficient = p->coefficient * q->coefficient; // 次数 temp->degree = p->degree + q->degree; temp->next = nullptr; // 将temp插入到结果链表中 LinkedList insertNode = findPre(head, temp->degree); if (insertNode->next == nullptr) { insertNode->next = temp; } else if (insertNode->next->degree == temp->degree) { insertNode->next->coefficient += temp->coefficient; free(temp); } else if (insertNode->next->degree < temp->degree) { temp->next = insertNode->next; insertNode->next = temp; } q = q->next; } p = p->next; } return head;}void printLinkList(LinkedList L) { LNode *p = L->next; while (p != nullptr) { cout << p->coefficient << "x^" << p->degree << " "; p = p->next; } cout << endl;}int main() { LinkedList L1 = (LinkedList) malloc(sizeof(LNode)); LinkedList L2 = (LinkedList) malloc(sizeof(LNode)); L1->next = nullptr; L2->next = nullptr; for (int i = 0; i < 3; i++) { LinkedList temp1 = (LinkedList) malloc(sizeof(LNode)); temp1->coefficient = (2 + i); temp1->degree = (1 + i); temp1->next = L1->next; L1->next = temp1; LinkedList temp2 = (LinkedList) malloc(sizeof(LNode)); temp2->coefficient = (4 + i); temp2->degree = (i); temp2->next = L2->next; L2->next = temp2; } printLinkList(L1); printLinkList(L2); LinkedList result = calculate(L1, L2); printLinkList(result); return 0;}