C语言-一元稀疏多项式计算器

#include<stdio.h> #include<stdlib.h> #pragma warning(disable:4996) typedef struct poly//多项式的每一项结构 { double coeff;//系数 int index;//指数 struct poly* next;//指针 }node; struct poly* CreatePoly();//创建链表 void Sort(struct poly* head);//排序 void AddSub(struct poly* head1, struct poly* head2);//加减法 void Mul(struct poly* head1, struct poly* head2);//相乘 void ShowPoly(struct poly* head);//输出 int count; void main() { int choice, i; node* head1 = NULL; node* head2 = NULL; do { system("cls"); printf("\n"); printf("一元稀疏多项式计算器\n"); printf("1 输入多项式 A和B \n"); printf("2 计算A + B\n"); printf("3 计算A - B\n"); printf("4 计算B - A\n"); printf("5 计算A * B\n"); printf("0 退出程序\n\n"); printf("注意首次计算时必须先输入多项式！\n"); printf("请输入您的选项："); scanf("%d", &choice); switch (choice) { case 0: break; case 1: { count = 0; printf("\n输入时请注意每项的指数不能相同！\n"); head1 = CreatePoly(); head2 = CreatePoly(); system("pause"); break; } case 2: { if (head1 == NULL) { count = 1; printf("A多项式不存在！\n"); system("pause"); break; } if (head2 == NULL) { count = 2; printf("B多项式不存在！"); system("pause"); break; } count = 2; printf(" 多项式 A = "); ShowPoly(head1); printf(" 多项式 B = "); ShowPoly(head2); AddSub(head1, head2); system("pause"); break; } case 3: { if (head1 == NULL) { count = 1; printf("A多项式不存在！\n"); system("pause"); break; } if (head2 == NULL) { count = 2; printf("B多项式不存在！"); system("pause"); break; } count = 3; printf(" 多项式 A = "); ShowPoly(head1); printf(" 多项式 B = "); ShowPoly(head2); AddSub(head1, head2); system("pause"); break; } case 4: { if (head1 == NULL) { count = 1; printf("A多项式不存在！\n"); system("pause"); break; } if (head2 == NULL) { count = 2; printf("B多项式不存在！"); system("pause"); break; } count = 4; printf(" 多项式 A = "); ShowPoly(head1); printf(" 多项式 B = "); ShowPoly(head2); AddSub(head2, head1); system("pause"); break; } case 5: { if (head1 == NULL) { count = 1; printf("A多项式不存在！\n"); system("pause"); break; } if (head2 == NULL) { count = 2; printf("B多项式不存在！"); system("pause"); break; } count = 5; printf(" 多项式 A = "); ShowPoly(head1); printf(" 多项式 B = "); ShowPoly(head2); Mul(head1, head2); system("pause"); break; } } } while (choice); } struct poly* CreatePoly() { node* head = NULL, * p1, * p2 = NULL; int n;//项数 int i; count++; printf("请输入多项式"); if (count == 1) printf(" A "); else printf(" B "); printf("的 项数："); scanf("%d", &n); head = (struct poly*)malloc(sizeof(struct poly));//动态创建链表 for (i = 1; i <= n; i++) { if ((p1 = (struct poly*)malloc(sizeof(struct poly))) == NULL) { printf("ERROR"); exit(0); } p1->next = NULL; printf(" 请输入多项式"); if (count == 1) printf(" A "); else printf(" B "); printf("的第 %d 项系数和指数：", i); scanf("%lf", &p1->coeff); scanf("%d", &p1->index); if (i == 1)head->next = p1;//输入是第一项时，头节点指针指向第一项 else p2->next = p1;//连接链表 p2 = p1; } printf("多项式"); if (count == 1) printf(" A = "); else printf(" B = "); Sort(head); ShowPoly(head); printf("**************************\n"); return head; } void Sort(struct poly* head) { node* p1, * curr, * pre, * p2;//新建链表 p1 = head->next;//p1指针所指向的结点要逐个取出作为插入结点 head->next = NULL;//head指针带头结点，初始为空链表 while (p1 != NULL)//p1指针不为空时循环 { curr = head->next; pre = head; //定位插入位置，退出循环时，pre指针向要插入节点的位置 while (curr != NULL && curr->index >= p1->index) { pre = curr; curr = curr->next; } p2 = p1; //p2指针指向要插入结点的位置 p1 = p1->next;//p1指针指向下一个结点 //p2指针所指结点插入pre指针所指结点后 p2->next = pre->next; pre->next = p2; } } void AddSub(struct poly* head1, struct poly* head2) { node* head = NULL;//新建链表储存相加后多项式 node* p1 = NULL;//中间变量 node* p2 = NULL;//保留前一个结点 node* p = NULL;//第一个多项式的循环变量 node* pp = NULL;//第二个多项式的循环变量 if ((head = (struct poly*)malloc(sizeof(struct poly))) == NULL) { printf("ERROR"); exit(0); } head->next = NULL; for (pp = head2->next; pp != NULL; pp = pp->next) //复制第二个多项式链表 { if ((p1 = (struct poly*)malloc(sizeof(struct poly))) == NULL) { printf("ERROR"); exit(0); } p1->next = NULL; if (count == 2)p1->coeff = pp->coeff;//加法直接复制 if (count == 3 || count == 4)p1->coeff = (-1.0) * pp->coeff;//减法取相反数 p1->index = pp->index; if (head->next == NULL)head->next = p1; else p2->next = p1; p2 = p1; } for (p = head1->next; p != NULL; p = p->next) //循环多项式的每一项 { for (pp = head->next, p2 = head; pp != NULL; ) { if (p->index == pp->index) //指数相等 { pp->coeff = p->coeff + pp->coeff;//系数相加 if (pp->coeff == 0) { pp = pp->next; p2->next = pp; } else { pp = pp->next; p2 = p2->next; } break; } if (pp->next == NULL) //没有相同指数项，创建添加 { if ((p1 = (struct poly*)malloc(sizeof(struct poly))) == NULL) { printf("ERROR"); exit(0); } p1->next = NULL; p1->coeff = p->coeff;//多余项添加到新建链表 p1->index = p->index; p1->next = head->next; head->next = p1; pp = pp->next; p2 = p2->next; break; } pp = pp->next; p2 = p2->next; } } if (count == 2) printf(" A + B = "); if (count == 3) printf(" A - B = "); if (count == 4) printf(" B - A = "); Sort(head); ShowPoly(head); printf(" ━━━━━━━━━━━━━━━━━━━━\n"); } void Mul(struct poly* head1, struct poly* head2) { node* head = NULL;//相乘后的多项式所有项的链表头节点 node* p1 = NULL;//中间变量 node* p2 = NULL;//保留前一个结点 node* p = NULL;//第一个多项式的循环变量 node* pp = NULL;//第二个多项式的循环变量 if ((head = (struct poly*)malloc(sizeof(struct poly))) == NULL) { printf("ERROR"); exit(0); } head->next = NULL; //两个循环建立多项式相乘后所有项的存储链表 for (p = head1->next; p != NULL; p = p->next) { for (pp = head2->next; pp != NULL; pp = pp->next) { if ((p1 = (struct poly*)malloc(sizeof(struct poly))) == NULL) { printf("ERROR"); exit(0); } p1->next = NULL; p1->coeff = p->coeff * pp->coeff;//系数相乘 p1->index = p->index + pp->index;//指数相加 if (head->next == NULL)head->next = p1;//添加到新建链表 else p2->next = p1; p2 = p1; } } for (p = head->next; p != NULL; p = p->next) //合并多项式，相同指数项合并 { for (pp = p->next, p2 = p; pp != NULL; pp = pp->next, p2 = p2->next) { if (p->index == pp->index) { p->coeff = p->coeff + pp->coeff; pp = pp->next; p2->next = pp; } } } if (count == 5)printf(" A * B = "); Sort(head); ShowPoly(head); printf(" ━━━━━━━━━━━━━━━━━━━━\n"); } void ShowPoly(struct poly* head)//输出函数 { struct poly* p = NULL; int i; for (p = head->next, i = 0; p != NULL; p = p->next, i++) { if (p->index == 0) { if (p->coeff == 0) break; else printf("%.2lf", p->coeff); } else if (p->index == 1) { if (p->coeff == 1) printf("x"); else if (p->coeff == -1) printf("-x"); else printf("%.2lfx", p->coeff); }