数据结构:单向链表系列5--在链表中查找元素

在链表中查找元素

函数签名：

bool search(Node *head, int x) 

如果在链表中查找到这个元素返回true,否则false

迭代法

2) 初始化一个节点指针, current = head.
3) 如果current不为NULL执行以下循环
    a) current->key 等于当前待查找值key则返回true.
    b) current = current->next
4) 否则返回 false 

/*Checks whether the value key is present in linked list*/
bool search(struct Node* head, int key)
{
    struct Node* current = head; //Initialize current

    while(current != NULL)
    {
        if(current->data == key)
            return true;
        current = current->next;
    }

    return false;
}

java：

  //Checks whether the value key is present in linked list 
    public boolean search(Node head, int key) 
    { 
        Node current = head;    //Initialize current 
        while (current != null) 
        { 
            if (current.data == key) 
                return true;    //data found 
            current = current.next; 
        } 
        return false;    //data not found 
    }

c#

  // Checks whether the value key is present in linked list 
    public bool search(Node head, int key) 
    { 
        Node current = head; // Initialize current 
        while (current != null) 
        { 
            if (current.data == key) 
                return true; // data found 
            current = current.next; 
        } 
        return false; // data not found 
    } 

递归法：

bool search(head, x)
1)如果head是NULL, return false.
2) 如果head数据域的值和待查找的一致，返回true;
2) 否则返回 search(head->next, x) 

c语言：

/*
    Checks whether the value key is present in linked list
 */
bool searchRecursive(struct Node* head, int key)
{
    if(head == NULL)
    {
        return false;
    }

    //If key is present in current node,
    //return true
    if(head->data == key)
        return true;

    //recursive for remaining list
    return searchRecursive(head->next, key);
}

 java:

  // Checks whether the value key is present 
    // in linked list 
    public boolean search(Node head, int key) 
    { 
        // Base case 
        if (head == null) 
            return false; 
  
        // If key is present in current node, 
        // return true 
        if (head.data == key) 
            return true; 
  
        // Recur for remaining list 
        return search(head.next, key); 
    } 

c#

// Checks whether the value key is present 
    // in linked list 
    public bool search(Node head, int key) 
    { 
        // Base case 
        if (head == null) 
            return false; 
  
        // If key is present in current node, 
        // return true 
        if (head.data == key) 
            return true; 
  
        // Recur for remaining list 
        return search(head.next, key); 
    } 

 文章来源：https://www.geeksforgeeks.org/search-an-element-in-a-linked-list-iterative-and-recursive/