程式碼示例：

#define _CRT_SECURE_NO_WARNINGS

#include <stdio.h>

#include <stdlib.h>

typedef struct Pol

{

int coe; // 係數

int index; // 指數

struct Pol *next;

}Pol;

int main(int argc, char *argv[])

{

Pol *head1 = NULL; // 第一個多項式

Pol *head2 = NULL; // 第二個多項式

Pol *Initiate(Pol *head1); // 宣告初始化函式

void Output(Pol *head); // 宣告輸出函式

void PolAdd(Pol *head1, Pol *head2); // 宣告相加函式

int coe, index;

char sign;

Pol *p;

int n = 0;

// 初始化第一個多項式

head1 = Initiate(head1);

p = head1;

while (1)

{

scanf("%dx%d%c", &coe, &index, &sign);

p->next = (Pol *)malloc(sizeof(Pol));

p = p->next;

p->coe = coe;

p->index = index;

p->next = NULL;

if(sign == "\n")

break;

}

printf("第一多項式輸入完畢。\n");

// 初始化第二個多項式

head2 = Initiate(head2);

p = head2;

while (1)

{

scanf("%dx%d%c", &coe, &index, &sign);

p->next = (Pol *)malloc(sizeof(Pol));

p = p->next;

p->coe = coe;

p->index = index;

p->next = NULL;

if (sign == "\n")

break;

}

printf("第二多項式輸入完畢。\n");

// 呼叫相加函式和輸出函式

PolAdd(head1, head2);

Output(head1);

system("PAUSE");

return 0;

}

// 初始化連結串列函式

Pol *Initiate(Pol *head)

{

head = (Pol *)malloc(sizeof(Pol));

head->next = NULL;

return head;

}

// 初始化相加函式

void PolAdd(Pol *head1, Pol *head2)

{

Pol *p = head1->next;

Pol *q = head2->next;

Pol *pre = head1;

Pol *temp = NULL;

int sum;

while ((p != NULL) && (q != NULL))

{

if (p->index < q->index)

{

pre->next = p;

pre = pre->next;

p = p->next;

}

else if(p->index == q->index)

{

sum = p->coe + q->coe;

if (sum != 0)

{

p->coe = sum;

pre->next = p;

pre = pre->next;

p = p->next;

temp = q;

q = q->next;

free(temp);

}

else

{

temp = p;

p = p->next;

free(temp);

temp = q;

q = q->next;

free(temp);

}

}

else

{

pre->next = q;

pre = pre->next;

q = q->next;

}

}

// 兩串長度不相等時，把尾部一次加入

if (p != NULL)

pre->next = p;

else

pre->next = q;

}

// 輸出函式

void Output(Pol *head)

{

Pol *p = head;

p = p->next;

int i = 0;

while (p)

{

if (p->coe > 0 && i != 0)

{

printf("+%dX^%d", p->coe, p->index);

p = p->next;

}

else

{

printf("%dX^%d", p->coe, p->index);

p = p->next;

}

i++;

}

}