通过数据结构的知识编写一个程序。建立单链表，在单链表中实现插入，删除和查找操作。将两个递增的有序单链表合并成一个非递减的有序单链表，不能用Python编程

在没有Python的情况下，我们可以选择一种常见的编程语言如C++来实现这个功能。首先，我们定义一个链表节点的数据结构：

struct ListNode {
    int val;
    ListNode* next;
    ListNode(int x) : val(x), next(nullptr) {}
};

接下来，我们实现单链表的基本操作：

1. 插入元素:

void insert(ListNode*& head, int val) {
    ListNode* newNode = new ListNode(val);
    if (!head) {
        head = newNode;
    } else {
        ListNode* curr = head;
        while (curr->next && curr->next->val < val) {
            curr = curr->next;
        }
        newNode->next = curr->next;
        curr->next = newNode;
    }
}

2. 删除元素:

ListNode* deleteNode(ListNode* head, int target) {
    if (!head || !head->val) return head;

    if (head->val == target) {
        ListNode* temp = head;
        head = head->next;
        delete temp;
        return head;
    }

    ListNode* curr = head;
    while (curr->next && curr->next->val != target) {
        curr = curr->next;
    }
    if (curr->next) {
        curr->next = curr->next->next;
        delete curr->next;
    }
    return head;
}

3. 查找元素:

bool search(ListNode* head, int target) {
    ListNode* curr = head;
    while (curr) {
        if (curr->val == target) return true;
        curr = curr->next;
    }
    return false;
}

然后，合并两个递增有序链表：

ListNode* mergeSortedLists(ListNode* l1, ListNode* l2) {
    ListNode* dummyHead = new ListNode(0);
    ListNode* tail = dummyHead;
    
    while (l1 && l2) {
        if (l1->val <= l2->val) {
            tail->next = l1;
            l1 = l1->next;
        } else {
            tail->next = l2;
            l2 = l2->next;
        }
        tail = tail->next;
    }
    
    if (l1) tail->next = l1;
    else tail->next = l2;
    
    return dummyHead->next;
}