C语言单链表操作：创建、删除、插入、查找

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

// 定义链表结点 typedef struct Node { int data; struct Node* next; } Node;

// 创建链表 Node* createLinkedList() { Node* head = NULL; Node* tail = NULL;

int num;
scanf("%d", &num);

while (num != 0) {
    Node* newNode = (Node*)malloc(sizeof(Node));
    newNode->data = num;
    newNode->next = NULL;

    if (head == NULL) {
        head = newNode;
        tail = newNode;
    } else {
        tail->next = newNode;
        tail = newNode;
    }  
    scanf("%d", &num);
}

return head;

}

// 输出链表所有元素 void printLinkedList(Node* head) { Node* current = head;

while (current != NULL) {
    printf("%d ", current->data);
    current = current->next;
}

printf("\n");

}

// 删除第一个元素 Node* deleteFirstNode(Node* head) { if (head == NULL) { return NULL; }

Node* temp = head;
head = head->next;
free(temp);

return head;

}

// 计算链表长度 int getLinkedListLength(Node* head) { int length = 0; Node* current = head;

while (current != NULL) {
    length++;
    current = current->next;
}

return length;

}

// 在第二个元素处插入新元素 Node* insertElement(Node* head, int element) { Node* newNode = (Node*)malloc(sizeof(Node)); newNode->data = element;

if (head == NULL) {
    newNode->next = NULL;
    return newNode;
}

Node* current = head;
int count = 1;

while (current->next != NULL && count < 2) {
    current = current->next;
    count++;
}

newNode->next = current->next;
current->next = newNode;

return head;

}

// 查找元素所在位置 int findElement(Node* head, int element) { int position = 1; Node* current = head;

while (current != NULL) {
    if (current->data == element) {
        return position;
    }

    current = current->next;
    position++;
}

return -1;

}

int main() { // 创建链表 Node* A = createLinkedList();

// 输出所有元素
printLinkedList(A);

// 删除第一个元素
A = deleteFirstNode(A);

// 输出删除后的元素
printLinkedList(A);

// 输出链表长度
int length = getLinkedListLength(A);
printf("%d\n", length);

// 在第二个元素处插入新元素
A = insertElement(A, 100);

// 输出第一个元素100所在位置
int position = findElement(A, 100);
printf("%d\n", position);

return 0;

}