结合链表的基本运算，完成两个及以上多项式合并同类项实验 。 P1 2x+3x7+5x” P2 20x+4x+5元+90 S:20x+6x=+58+4x7×5+0 ​用c语言写写一个整的代码

在C语言中，我们可以创建一个结构体来表示多项式的每个项，并利用链表的数据结构来存储多项式。这里是一个简单的示例，演示如何合并两个多项式并去除重复项：

#include <stdio.h>
#include <stdlib.h>

typedef struct Term {
    int coefficient;
    int exponent;
    struct Term* next;
} Term;

// 初始化链表头结点
Term* createTerm(int coef, int exp) {
    Term* new_term = (Term*)malloc(sizeof(Term));
    new_term->coefficient = coef;
    new_term->exponent = exp;
    new_term->next = NULL;
    return new_term;
}

// 合并两个多项式并去重
Term* mergePolynomials(Term* poly1, Term* poly2) {
    // 遍历poly2
    while (poly2 != NULL) {
        int merged = 0; // 标记是否已添加到结果中
        Term* current = poly1;

        // 检查poly1中的每一项是否需要更新
        while (current != NULL && !merged) {
            if (current->exponent == poly2->exponent && 
                current->coefficient + poly2->coefficient > 0) { // 如果系数相加大于0说明可以合并
                current->coefficient += poly2->coefficient;
                merged = 1;
            } else {
                current = current->next;
            }
        }

        // 如果poly1中未找到合适的位置，将poly2的项插入
        if (!merged) {
            current = createTerm(poly2->coefficient, poly2->exponent);
            if (poly1 == NULL) {
                poly1 = current;
            } else {
                Term* last = poly1;
                while (last->next != NULL) {
                    last = last->next;
                }
                last->next = current;
            }
        }

        poly2 = poly2->next;
    }

    return poly1;
}

// 打印多项式
void printPolynomial(Term* poly) {
    if (poly == NULL) {
        printf("0\n");
        return;
    }
    
    Term* temp = poly;
    while (temp != NULL) {
        printf("%dx^%d", temp->coefficient, temp->exponent);
        if (temp->next != NULL) {
            printf("+");
        }
        temp = temp->next;
    }
    printf("\n");
}

int main() {
    // 定义两个多项式
    Term* poly1 = createTerm(2, 1); // 2x + 3x^7 + 5x
    poly1->next = createTerm(3, 7);
    poly1->next->next = createTerm(5, 1);

    Term* poly2 = createTerm(20, 1); // 20x + 4x + 5x^4 + 90
    poly2->next = createTerm(4, 1);
    poly2->next->next = createTerm(5, 4);
    poly2->next->next->next = createTerm(90, 0); // 90表示常数项

    // 合并多项式
    Term* result = mergePolynomials(poly1, poly2);

    // 打印结果
    printf("合并后的多项式：\n");
    printPolynomial(result);

    return 0;
}

这个程序首先初始化了两个多项式，然后通过`mergePolynomials`函数合并它们并去除重复项。最后，`printPolynomial`函数用于打印合并后的多项式。