数据结构（2-5~2-8）

2-5编写算法，在单链表中查找第一值为x的结点，并输出其前驱和后继的存储位置

#include
#include

typedef int DataType; 
struct Node
{
    DataType      data; 
    struct Node*  next;  
};
typedef struct Node  *PNode;    
typedef struct Node  *LinkList;   


LinkList SetNullList_Link() //设置头结点
{
    LinkList head = (LinkList)malloc(sizeof(struct Node));
    if (head != NULL) head->next = NULL;
    else printf("alloc failure");
    return head; 
}

void CreateList_Tail(struct Node* head)//利用尾插法
{
    PNode p = NULL;
    PNode q = head;
    DataType data;
    scanf("%d", &data);
    while (data != -1)
    {   
        p = (struct Node*)malloc(sizeof(struct Node));
        p->data = data;
        p->next = NULL;
        q->next = p;
        q = p;
        scanf("%d", &data);
    }
}
int Inserch_num(LinkList head,int x)//找值 
{
   LinkList p;
   int i=0;
   p=head->next;
   while(p)//把前后特殊情况单列出来 
   {
    if(i==0&&p->data==x)
    {
     printf("The Prodrove node is head,the position of the rear  node is at position 2 of the linked list\n");
     return 0;
	}
	 if(p->data==x&&p->next==NULL)
	{
         printf("The Prodrove node is %d,there is no rear node\n ",i);
       return 0;
	}
	 if(p->data==x)
	{
	   printf("The Prodrove node is %d,he rear node is %d\n",i,i+2); 
      return 0;
	}
     i++;
     p = p->next;
   }
   return 0;
}
void print(LinkList head)   //打印
{
    PNode  p = head->next;
    while (p)
    {
        printf("%d ", p->data);
        p = p->next;
    }
}
void DestoryList_Link(LinkList head)  //销毁链表
{
    PNode  pre = head; 
    PNode p = pre->next;
    while (p)
    {
        free(pre);
        pre = p;
        p = pre->next;
    }
    free(pre);
}

int main()
{
    LinkList head = NULL;
    int x=0,a=0;
    head = SetNullList_Link();
    CreateList_Tail(head);
    print(head);
    printf("\n");
    printf("Please input the number you find:");
    scanf("%d",&x);
    a=x;
    Inserch_num(head,a);
   DestoryList_Link(head);
    return 0;
}

2-6在单循环链表中，编写算法实现将链表中数据域为奇数的结点移至表头，将链表中数据域为偶数的结点移至表尾

#include
#include

typedef int DataType; 
struct Node {
    DataType      data; 
    struct Node*  next;  
};
typedef struct Node  *PNode;    
typedef struct Node  *LinkList;   

LinkList CreateList_Tail_loop()
{
    LinkList head = (LinkList)malloc(sizeof(struct Node));
    PNode cur = NULL;
    PNode tail = head;
    DataType data;
    scanf("%d", &data);
    while (data != -1)
    {   
        cur = (struct Node*)malloc(sizeof(struct Node));
        cur->data = data;
        tail->next = cur;
        tail = cur;
        scanf("%d", &data);
    }
    tail->next = head;
    return tail;
}
PNode Move_Odd_Even(LinkList tail)
{
    PNode head=tail->next,pre=head->next,q=pre->next;
    PNode pre1,head1=(PNode)malloc(sizeof(struct Node));
    PNode pre2,head2=(PNode)malloc(sizeof(struct Node));
    pre1=head1;
    pre2=head2;
    while(q!=head->next)
    {
        if(pre->data%2==0)
        {
            pre->next=pre1->next;
            pre1->next=pre;
            pre1=pre;
        }
        else
        {
            pre->next=pre2;
            pre2->next=pre;
            pre2=pre;
        }
    pre=q;
    q=q->next;
    }
head1=head1->next;
pre2->next=head1;
pre1->next=head2;
return pre1;
}
void print(LinkList tail)    
{
    PNode  head = tail->next;
    PNode p = head->next;
    while (p != head)
    {
        printf("%d ", p->data);
        p = p->next;
    }
}

void DestoryList_Link(LinkList tail)
{
    PNode pre = tail->next;
    PNode p = pre->next;
    while (p != tail)
    {
        free(pre);
        pre = p;
        p = pre->next;
    }
    free(pre);
    free(tail);
}

int main()
{
    LinkList tail = NULL;
    LinkList p = NULL;
    tail = CreateList_Tail_loop();
    p = Move_Odd_Even(tail);
    print(p);
    DestoryList_Link(tail);
    return 0;
}

2-7将两个有序线性表LIST1=（a1,a2,…，an）和LIST2=（b1,b2,…,bn）链接成一个有序线性链表LIST3,并删除LIST3链表中相同的结点，即链接中若有多个结点具有相同的数据域，只保留一个结点，使得顺序表中所有结点的数据域都不相同。在采用顺序表和单链表两种形式下分别设计算法实现上述功能

#include 
#include 

#define MAX_SIZE 100

void mergeAndRemoveDuplicates(int list1[], int list2[], int n1, int n2, int list3[]) {
    int i = 0, j = 0, k = 0;
    
    while (i < n1 && j < n2) {
        if (list1[i] < list2[j]) {
            list3[k] = list1[i];
            i++;
            k++;
        } else if (list1[i] > list2[j]) {
            list3[k] = list2[j];
            j++;
            k++;
        } else {  // 相同元素
            list3[k] = list1[i];
            i++;
            j++;
            k++;
        }
    }
    
    while (i < n1) {
        list3[k] = list1[i];
        i++;
        k++;
    }
    
    while (j < n2) {
        list3[k] = list2[j];
        j++;
        k++;
    }
}

void removeDuplicates(int list[], int size) {
    int i, j, k;
    
    for (i = 0; i < size; i++) {
        for (j = i + 1; j < size;) {
            if (list[j] == list[i]) {
                for (k = j; k < size - 1; k++) {
                    list[k] = list[k + 1];
                }
                size--;
            } else {
                j++;
            }
        }
    }
}

int main() {
	int i = 0; 
    int list1[] = {1, 2, 3, 5, 7};
    int list2[] = {3, 4, 5, 6, 8};
    int n1 = sizeof(list1) / sizeof(list1[0]);
    int n2 = sizeof(list2) / sizeof(list2[0]);
    
    int list3[MAX_SIZE];
    
    mergeAndRemoveDuplicates(list1, list2, n1, n2, list3);
    removeDuplicates(list3, n1 + n2);
    
    printf("Merged and duplicates removed list: ");
    for ( i = 0; i <8; i++) {
        printf("%d \n", list3[i]);
    }
    printf("\n");
    
    return 0;
}

#include 
#include 

struct ListNode {
    int val;
    struct ListNode* next;
};

struct ListNode* createNode(int val) {
    struct ListNode* newNode = (struct ListNode*)malloc(sizeof(struct ListNode));
    newNode->val = val;
    newNode->next = NULL;
    return newNode;
}

struct ListNode* mergeAndRemoveDuplicates(struct ListNode* list1, struct ListNode* list2) {
    struct ListNode* p = list1;
    struct ListNode* q = list2;
    struct ListNode* list3 = NULL; // 指向结果链表的头节点
    struct ListNode* tail = NULL; // 指向结果链表的尾节点
    
    while (p && q) {
        if (p->val < q->val) {
            // 若当前元素小于另一个表的当前元素，则将当前元素插入到结果链表中
            if (list3 == NULL) {
                list3 = tail = createNode(p->val);
            } else {
                tail->next = createNode(p->val);
                tail = tail->next;
            }
            p = p->next;
        } else if (p->val > q->val) {
            // 若当前元素大于另一个表的当前元素，则将当前元素插入到结果链表中
            if (list3 == NULL) {
                list3 = tail = createNode(q->val);
            } else {
                tail->next = createNode(q->val);
                tail = tail->next;
            }
            q = q->next;
        } else {  // 相同元素，只保留一个
            if (list3 == NULL) {
                list3 = tail = createNode(p->val);
            } else {
                tail->next = createNode(p->val);
                tail = tail->next;
            }
            p = p->next;
            q = q->next;
        }
    }
    
    // 将剩余的元素插入结果链表中
    while (p) {
        tail->next = createNode(p->val);
        tail = tail->next;
        p = p->next;
    }
    
    while (q) {
        tail->next = createNode(q->val);
        tail = tail->next;
        q = q->next;
    }
    
    // 删除结果链表中重复的元素
    struct ListNode* cur = list3;
    while (cur && cur->next) {
        if (cur->val == cur->next->val) {
            struct ListNode* temp = cur->next;
            cur->next = cur->next->next;
            free(temp);
        } else {
            cur = cur->next;
        }
    }
    
    return list3;
}

void printList(struct ListNode* head) {
    struct ListNode* cur = head;
    while (cur != NULL) {
        printf("%d ", cur->val);
        cur = cur->next;
    }
    printf("\n");
}

int main() {
    struct ListNode* list1 = createNode(1);
    list1->next = createNode(2);
    list1->next->next = createNode(3);
    list1->next->next->next = createNode(5);
    list1->next->next->next->next = createNode(7);
    
    struct ListNode* list2 = createNode(3);
    list2->next = createNode(4);
    list2->next->next = createNode(5);
    list2->next->next->next = createNode(6);
    list2->next->next->next->next = createNode(8);
    
    struct ListNode* list3 = mergeAndRemoveDuplicates(list1, list2);
    
    printf("Merged and duplicates removed list: ");
    printList(list3);
    
    // 释放链表的内存空间
    struct ListNode* temp;
    while (list3) {
        temp = list3;
        list3 = list3->next;
        free(temp);
    }
    
    return 0;
}

2-8设双链表中的结点包括4个部分：前驱指针llink，后继指针rlink，数据域data，访问频度freq，初始时将各结点的freq设置为0。当对某结点访问时使该结点的freq增加1，并且将链表按照访问freq递减的顺序进行排序。请编写算法实现以上功能

#include 
#include 

struct DoubleListNode {
    int data;
    int freq;
    struct DoubleListNode* llink;
    struct DoubleListNode* rlink;
};

struct DoubleListNode* createNode(int data) {
    struct DoubleListNode* newNode = (struct DoubleListNode*)malloc(sizeof(struct DoubleListNode));
    if (newNode == NULL) {
        printf("Memory allocation failed.\n");
        exit(1);
    }
    newNode->data = data;
    newNode->freq = 0;
    newNode->llink = NULL;
    newNode->rlink = NULL;
    return newNode;
}

void insertNode(struct DoubleListNode** head, int data) {
    struct DoubleListNode* newNode = createNode(data);
    
    if (*head == NULL) {
        *head = newNode;
        return;
    }
    
    // 插入到链表头部
    newNode->rlink = *head;
    (*head)->llink = newNode;
    *head = newNode;
}

void increaseFreq(struct DoubleListNode** head, int data) {
    if (*head == NULL) {
        return;
    }
    
    struct DoubleListNode* cur = *head;
    
    while (cur != NULL) {
        if (cur->data == data) {
            cur->freq++;
            
            // 调整链表顺序
            struct DoubleListNode* prev = cur->llink;
            while (prev != NULL && prev->freq < cur->freq) {
                struct DoubleListNode* next = cur->rlink;
                
                if (prev->llink) {
                    prev->llink->rlink = cur;
                }
                cur->llink = prev->llink;
                
                cur->rlink = prev;
                prev->llink = cur;
                
                if (next) {
                    next->llink = prev;
                }
                prev->rlink = next;
                
                prev = cur->llink;
            }
            
            break;
        }
        
        cur = cur->rlink;
    }
}

void printList(struct DoubleListNode* head) {
    struct DoubleListNode* cur = head;
    while (cur != NULL) {
        printf("(%d,%d) ", cur->data, cur->freq);
        cur = cur->rlink;
    }
    printf("\n");
}

void freeList(struct DoubleListNode* head) {
    struct DoubleListNode* cur = head;
    while (cur != NULL) {
        struct DoubleListNode* temp = cur;
        cur = cur->rlink;
        free(temp);
    }
}

int main() {
    struct DoubleListNode* head = NULL;
    
    insertNode(&head, 3);
    insertNode(&head, 5);
    insertNode(&head, 2);
    insertNode(&head, 8);
    
    printf("Original list: ");
    printList(head);
    
    increaseFreq(&head, 2);
    increaseFreq(&head, 5);
    increaseFreq(&head, 3);
    
    printf("Updated list: ");
    printList(head);
    
    // 释放链表的内存空间
    freeList(head);
    
    return 0;
}