我输入两个链表以负数结束合并链表C语言

以下是一个示例程序，可以实现输入两个链表并合并它们：

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

// 链表节点结构体
struct ListNode {
    int val;
    struct ListNode *next;
};

// 创建新节点
struct ListNode* createNode(int val) {
    struct ListNode* node = (struct ListNode*)malloc(sizeof(struct ListNode));
    node->val = val;
    node->next = NULL;
    return node;
}

// 合并两个链表
struct ListNode* mergeLists(struct ListNode* l1, struct ListNode* l2) {
    struct ListNode dummy = {0, NULL};
    struct ListNode* tail = &dummy;

    while (l1 && l2) {
        if (l1->val < l2->val) {
            tail->next = l1;
            l1 = l1->next;
        } else {
            tail->next = l2;
            l2 = l2->next;
        }
        tail = tail->next;
    }

    tail->next = l1 ? l1 : l2;
    return dummy.next;
}

// 释放链表内存
void freeList(struct ListNode* head) {
    while (head) {
        struct ListNode* node = head;
        head = head->next;
        free(node);
    }
}

int main() {
    struct ListNode *l1 = NULL, *l2 = NULL;
    int val;

    // 输入第一个链表
    printf("Input the first list (separated by spaces, end with a negative number):\n");
    while (scanf("%d", &val) == 1 && val >= 0) {
        struct ListNode* node = createNode(val);
        if (!l1) l1 = node;
        else {
            struct ListNode* tail = l1;
            while (tail->next) tail = tail->next;
            tail->next = node;
        }
    }

    // 输入第二个链表
    printf("Input the second list (separated by spaces, end with a negative number):\n");
    while (scanf("%d", &val) == 1 && val >= 0) {
        struct ListNode* node = createNode(val);
        if (!l2) l2 = node;
        else {
            struct ListNode* tail = l2;
            while (tail->next) tail = tail->next;
            tail->next = node;
        }
    }

    // 合并链表
    struct ListNode* merged = mergeLists(l1, l2);

    // 输出合并后的链表
    printf("Merged list:\n");
    struct ListNode* p = merged;
    while (p) {
        printf("%d ", p->val);
        p = p->next;
    }
    printf("\n");

    // 释放内存
    freeList(l1);
    freeList(l2);
    freeList(merged);

    return 0;
}

示例输入：

Input the first list (separated by spaces, end with a negative number):
1 3 5 7 9 -1
Input the second list (separated by spaces, end with a negative number):
2 4 6 8 10 -1

示例输出：

Merged list:
1 2 3 4 5 6 7 8 9 10