链表的并集

链表的并集

当有两个集合A,B求两个集合的并集
如: A = { 1, 2, 3 ,4}
B = { 3, 4, 5, 6}
A U B = { 1 ,2 ,3 ,4 ,5 ,6 };

结构体的创建,空链表创建

//定义结构体
struct Node;
typedef struct Node *Position;

struct Node
{
    int num;
    Position next;
};

//构建空的结构体
void Creat(Position &node)
{
    node = (Position)malloc(sizeof(struct Node));
    if (node == NULL)
        exit(0);

    node->next = NULL;
}

用定义Find函数来确保一个集合中没有重复的元素出现

int Find(Position node, int find)
{
    Position P = NULL;
    P = node;

    while (P != NULL && P->num != find)
        P = P->next;
    if(P != NULL)
        return P->num;

    return 0;
}

//插入新的数
void Inset(Position &node, int inset)
{
    if (node == NULL)
        Creat(node);

    //判断插入的数是否是不重复
    if (Find(node, inset) == 0)
    {
        Position P;
        P = (Position)malloc(sizeof(struct Node));
        if (P == NULL)
            exit(0);

        P->num = inset;
        P->next = node->next;
        node->next = P;
    }
}

接下来就需要将两个集合合并成一个集合

//将两个集合合成一个集合,写入新的链表中
Position ReCreat(Position H, Position L)
{
    Position R = NULL;

    //先确保两个链表都不指向最后NULL
    while (H != NULL && L != NULL)
        if (H->num > L->num)
        {
            Inset(R, H->num);
            H = H->next;
        }
        else if (H->num < L->num)
        {
            Inset(R, L->num);
            L = L->next;
        }
        //出现相同元素时
        else
        {
            Inset(R, H->num);
            H = H->next;
            L = L->next;
        }

    //如果一个链表还没有复制完,在进行复制
    while (L != NULL)
    {
        Inset(R, L->num);
        L = L->next;
    }

    while(H != NULL)
    {
        Inset(R, H->num);
        H = H->next;
    }

    return R;
}

源代码

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

//定义结构体
struct Node;
typedef struct Node *Position;

struct Node
{
    int num;
    Position next;
};

//构建空的结构体
void Creat(Position &node)
{
    node = (Position)malloc(sizeof(struct Node));
    if (node == NULL)
        exit(0);

    node->next = NULL;
}

int Find(Position node, int find)
{
    Position P = NULL;
    P = node;

    while (P != NULL && P->num != find)
        P = P->next;
    if(P != NULL)
        return P->num;

    return 0;
}

//插入新的数
void Inset(Position &node, int inset)
{
    if (node == NULL)
        Creat(node);

    //判断插入的数是否是不重复
    if (Find(node, inset) == 0)
    {
        Position P;
        P = (Position)malloc(sizeof(struct Node));
        if (P == NULL)
            exit(0);

        P->num = inset;
        P->next = node->next;
        node->next = P;
    }
}

//将两个集合合成一个集合,写入新的链表中
Position ReCreat(Position H, Position L)
{
    Position R = NULL;

    //先确保两个链表都不指向最后NULL
    while (H != NULL && L != NULL)
        if (H->num > L->num)
        {
            Inset(R, H->num);
            H = H->next;
        }
        else if (H->num < L->num)
        {
            Inset(R, L->num);
            L = L->next;
        }
        //出现相同元素时
        else
        {
            Inset(R, H->num);
            H = H->next;
            L = L->next;
        }

    //如果一个链表还没有复制完,在进行复制
    while (L != NULL)
    {
        Inset(R, L->num);
        L = L->next;
    }

    while(H != NULL)
    {
        Inset(R, H->num);
        H = H->next;
    }

    return R;
}


int main()
{
    Position H, L;
    H = NULL, L = NULL;
    int i, num;
    for (i = 0; i < 4; i++)
    {
        scanf("%d", &num);
        Inset(H, num);
    }
    for (i = 0; i < 4; i++)
    {
        scanf("%d", &num);
        Inset(L, num);
    }

    Position R = ReCreat(H->next, L->next);
    R = R->next;
    while (R)
    {
        printf("%d ", R->num);
        R = R->next;
    }

    system("pause");
    return 0;
}