C语言 用单链表存储一元多项式，并实现两个多项式相加运算。

本次代码纯c语言，可以支持输入两个多项式的项式、系数、指数。

实验目的：
1 掌握单链表的基本工作原理;
2 实现链式存储下的两个多项式的相加。
实验步骤
1 定义链式存储的数据结构
2 完成多项式的初始化，即给多项式赋初值
3 完成多项式的输出
4 实现多项式的相加及结果输出。

/* 采用CLion的外部控制台运行*/
#include
#include
#include
#include 

#define OK 1
#define ERROR 0
#define OVERFLOW -2
#define MAXSIZE 100    //最大长度


// 单链表的定义
typedef struct PNode {
    int coef;           //系数
    int expn;           //指数
    struct PNode *next; //节点的指针域
} PNode, *Polynomial;

void greatePolyn(Polynomial p, int num);            // 链表的初始化
void printout(Polynomial p, char num[]);            // 打印多项式
Polynomial AddPolyn(Polynomial ha, Polynomial hb);  //多项式相加
void returnMenu();                                  // 返回主界面
int menu();

PNode L1, L2;


// 链表的初始化
void greatePolyn(Polynomial p, int num) {
    Polynomial s;
    Polynomial pre, q;
    int n;
    printf("请输入第%d个多项式的项数：", num);
    scanf("%d", &n);
    p->next = NULL;
    pre = p;
    // 依次输入n个非零项
    for (int i = 1; i <= n; ++i) {
        s = (Polynomial) malloc(sizeof(PNode));
        s->next = NULL;
        printf("输入系数与指数");
        scanf("%d%d", &s->coef, &s->expn);

        q = p->next;
        while (q && q->expn < s->expn) {
            //通过比较指数找到第一个大于输入项指数的项*q
            pre = q;
            q = q->next;
        }
        s->next = q; //将输入项插入*q和其前驱节点pre之间
        pre->next = s;
        pre = s;
    }
    printf("第%d个多项式输入结束\n\n", num);
}


// 打印多项式
void printout(Polynomial p, char num[]) {
    int n = 0;
    Polynomial t = p;
    printf("\n%s\n", num);
    while ((t = t->next)) {
        n++;
    }
    p = p->next;
    for (int i = 1; i < n; i++) {
        if (p->coef != 0 && p->expn == 0)
            printf("%d+", p->coef);
        else if (p->coef < 0) {
            printf("\b%dx^%d+", p->coef, p->expn);
        } else
            printf("%dx^%d+", p->coef, p->expn);
        p = p->next;
    }

    if (p->coef < 0) {
        printf("\b%dx^%d", p->coef, p->expn);
    } else
        printf("%dx^%d", p->coef, p->expn);

    printf("\n");
}


// 两个多项式相加
Polynomial AddPolyn(Polynomial ha, Polynomial hb) {
    int c;
    Polynomial pa = ha->next, pb = hb->next, s, tc, hc;//将两个指针指向两个链表
    hc = (Polynomial) malloc(sizeof(PNode));//创建个新链表
    hc->next = NULL;
    tc = hc;//指针指向新链表
    while (pa != NULL && pb != NULL) {
        if (pa->expn > pb->expn) {
            s = (Polynomial) malloc(sizeof(PNode));
            s->expn = pb->expn;
            s->coef = pb->coef;
            tc->next = s;
            tc = s;
            pb = pb->next;
        } else if (pa->expn < pb->expn) {
            s = (Polynomial) malloc(sizeof(PNode));
            s->expn = pa->expn;
            s->coef = pa->coef;
            tc->next = s;
            tc = s;
            pa = pa->next;
        } else//遇到相同的指数，开始运算

        {
            c = pa->coef + pb->coef;
            if (c != 0) {
                s = (Polynomial) malloc(sizeof(PNode));
                s->expn = pa->expn;
                s->coef = c;
                tc->next = s;
                tc = s;
            }//c=0，就是直接跳下去
            pa = pa->next;
            pb = pb->next;
        }
    }
    if (pb != NULL)pa = pb;
    while (pa != NULL) {
        s = (Polynomial) malloc(sizeof(PNode));
        s->expn = pa->expn;
        s->coef = pa->coef;
        tc->next = s;
        tc = s;
        pa = pa->next;
    }
    tc->next = NULL;
    return hc;
}

// 返回主界面
void returnMenu() {
    printf("\n\n是否返回主界面？(y/n)\n");
    getchar();
    if (getchar() == 'y') {
        system("cls");
        menu();
    }
}


int menu() {
    Polynomial L;
    printf("\t多项式相加运算\t\n");
    printf("\t     1.多项式的创建\t\n");
    printf("\t     2.多项式的打印 \t\n");
    printf("\t     3.多项式的相加 \t\n");
    printf("=================================\n");
    printf("请输入要执行的操作: ");
    int l;
    scanf("%d", &l);
    switch (l) {
        case 1:
            system("cls");
            printf("请输入分别输入两个多项式：\n\n");
            for (int i = 1; i < 3; i++) {
                if (i == 1)
                    greatePolyn(&L1, i);
                else
                    greatePolyn(&L2, i);
            }
            returnMenu();
            break;
        case 2:
            system("cls");
            for (int i = 1; i < 3; i++) {
                if (i == 1)
                    printout(&L1, "第1个多项式如下");
                else
                    printout(&L2, "第2个多项式如下");
            }
            returnMenu();
            break;
        case 3:
            system("cls");
            L = AddPolyn(&L1, &L2);
            printout(L, " 相加后的多项式如下");
            returnMenu();
            break;
        default:
            printf("[输入错误]请重新输入有效数字!\n");
            Sleep(1000);
            system("cls");
            menu();
            break;
    }
}

int main() {
    menu();
}

 多项式的创建

多项式的打印

 

 多项式的相加