单链表的查找与插入代码c语言

单链表的查找与插入代码C语言实现如下：

1. 定义单链表节点结构体

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

2. 查找指定值的节点

struct ListNode* searchList(struct ListNode *head, int target) {
    struct ListNode *cur = head;
    while (cur != NULL && cur->val != target) {
        cur = cur->next;
    }
    return cur;
}

3. 在指定位置插入节点

void insertNode(struct ListNode **head, int pos, int val) {
    struct ListNode *newNode = (struct ListNode*)malloc(sizeof(struct ListNode));
    newNode->val = val;
    newNode->next = NULL;

    if (pos == 0) {
        newNode->next = *head;
        *head = newNode;
        return;
    }

    struct ListNode *prev = NULL;
    struct ListNode *cur = *head;
    int i = 0;
    while (cur != NULL && i < pos) {
        prev = cur;
        cur = cur->next;
        i++;
    }
    prev->next = newNode;
    newNode->next = cur;
}

完整代码如下：

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

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

struct ListNode* searchList(struct ListNode *head, int target) {
    struct ListNode *cur = head;
    while (cur != NULL && cur->val != target) {
        cur = cur->next;
    }
    return cur;
}

void insertNode(struct ListNode **head, int pos, int val) {
    struct ListNode *newNode = (struct ListNode*)malloc(sizeof(struct ListNode));
    newNode->val = val;
    newNode->next = NULL;

    if (pos == 0) {
        newNode->next = *head;
        *head = newNode;
        return;
    }

    struct ListNode *prev = NULL;
    struct ListNode *cur = *head;
    int i = 0;
    while (cur != NULL && i < pos) {
        prev = cur;
        cur = cur->next;
        i++;
    }
    prev->next = newNode;
    newNode->next = cur;
}

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 *head = NULL;
    insertNode(&head, 0, 1);
    insertNode(&head, 1, 2);
    insertNode(&head, 2, 3);

    printList(head);

    struct ListNode *target = searchList(head, 2);
    if (target != NULL) {
        printf("Found target node with value %d\n", target->val);
    } else {
        printf("Target node not found\n");
    }

    return 0;
}