将上面代码中的序列全部换成链表写

下面是将上述代码中的序列改为链表的实现：

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

typedef struct node {
    int val;
    struct node* next;
} Node;

int cmp(const void* a, const void* b) {
    return (*(int*)a - *(int*)b);
}

Node* createList(int n) {
    Node* head = NULL;
    Node* prev = NULL;

    for(int i = 0; i < n; i++) {
        Node* cur = (Node*)malloc(sizeof(Node));
        scanf("%d", &(cur->val));
        cur->next = NULL;

        if(head == NULL) {
            head = cur;
        }
        else {
            prev->next = cur;
        }
        prev = cur;
    }

    return head;
}

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

Node* mergeList(Node* a, Node* b) {
    Node* head = NULL;
    Node* cur = NULL;

    while(a != NULL && b != NULL) {
        Node* tmp = (Node*)malloc(sizeof(Node));
        if(a->val <= b->val) {
            tmp->val = a->val;
            a = a->next;
        }
        else {
            tmp->val = b->val;
            b = b->next;
        }

        tmp->next = NULL;
        if(head == NULL) {
            head = cur = tmp;
        }
        else {
            cur->next = tmp;
            cur = cur->next;
        }
    }

    if(a != NULL) {
        if(head == NULL) {
            head = a;
        }
        else {
            cur->next = a;
        }
    }
    else if(b != NULL) {
        if(head == NULL) {
            head = b;
        }
        else {
            cur->next = b;
        }
    }

    return head;
}

Node* findMid(Node* head) {
    Node* slow = head;
    Node* fast = head;

    while(fast != NULL && fast->next != NULL) {
        slow = slow->next;
        fast = fast->next->next;
    }

    return slow;
}

int main() {
    int n;
    scanf("%d", &n);

    Node* a = createList(n);
    Node* b = createList(n);

    Node* c = mergeList(a, b);

    // 排序
    int len = 2 * n;
    int arr[len];
    int i = 0;
    while(c != NULL) {
        arr[i] = c->val;
        c = c->next;
        i++;
    }
    qsort(arr, len, sizeof(int), cmp);

    // 构造链表
    Node* head = NULL;
    for(int i = 0; i < len; i++) {
        Node* tmp = (Node*)malloc(sizeof(Node));
        tmp->val = arr[i];
        tmp->next = head;
        head = tmp;
    }

    // 计算中位数
    Node* mid = findMid(head);
    if(len % 2 == 0) {
        printf("%d\n", (mid->val + mid->next->val) / 2);
    }
    else {
        printf("%d\n", mid->val);
    }

    return 0;
}

上述代码中，我们使用了链表来存储输入的序列。具体地，我们使用了链表的头插法来构造链表，使用了指针来遍历链表。在合并两个链表时，我们使用了归并排序的思想，将两个链表合并为一个有序链表。在计算中位数时，我们使用了快慢指针的方法来找到链表的中间节点。