Linked List (רשימה מקושרת)

1class Node:2    def __init__(self, value):3        self.value = value4        self.next = None5
6
7class LinkedList:8    def __init__(self):9        self.head = None10
11    def append(self, value):12        node = Node(value)13        if self.head is None:14            self.head = node15            return16        current = self.head17        while current.next:18            current = current.next19        current.next = node20
21    def find(self, value):22        current = self.head23        while current:24            if current.value == value:25                return True26            current = current.next27        return False28
29    def delete(self, value):30        # Re-link the previous node around the match31        current, prev = self.head, None32        while current:33            if current.value == value:34                if prev is None:35                    self.head = current.next36                else:37                    prev.next = current.next38                return True39            prev, current = current, current.next40        return False41
42    def __str__(self):43        values, current = [], self.head44        while current:45            values.append(str(current.value))46            current = current.next47        return " -> ".join(values) + " -> None"48
49
50lst = LinkedList()51for value in [3, 7, 1, 9]:52    lst.append(value)53
54print("List:    ", lst)55print("find(7): ", lst.find(7))56lst.delete(1)57print("After delete(1):", lst)

1class Node {2    constructor(value) {3        this.value = value;4        this.next = null;5    }6}7
8class LinkedList {9    constructor() {10        this.head = null;11    }12
13    append(value) {14        const node = new Node(value);15        if (!this.head) {16            this.head = node;17            return;18        }19        let current = this.head;20        while (current.next) current = current.next;21        current.next = node;22    }23
24    find(value) {25        for (let n = this.head; n; n = n.next) {26            if (n.value === value) return n;27        }28        return null;29    }30
31    delete(value) {32        if (!this.head) return false;33        if (this.head.value === value) {34            this.head = this.head.next;35            return true;36        }37        // Walk to the node just before the one to remove38        for (let n = this.head; n.next; n = n.next) {39            if (n.next.value === value) {40                n.next = n.next.next;41                return true;42            }43        }44        return false;45    }46
47    toArray() {48        const out = [];49        for (let n = this.head; n; n = n.next) out.push(n.value);50        return out;51    }52}53
54const list = new LinkedList();55for (const value of [10, 20, 30, 40]) list.append(value);56console.log("List:", list.toArray().join(" -> "));57console.log("find(30):", list.find(30) !== null);58list.delete(20);59console.log("After delete(20):", list.toArray().join(" -> "));

1public class Main {2    static class Node {3        int value;4        Node next;5        Node(int value) { this.value = value; }6    }7
8    static Node head;9
10    static void append(int value) {11        Node node = new Node(value);12        if (head == null) { head = node; return; }13        Node cur = head;14        while (cur.next != null) cur = cur.next;15        cur.next = node;16    }17
18    static boolean find(int value) {19        for (Node cur = head; cur != null; cur = cur.next) {20            if (cur.value == value) return true;21        }22        return false;23    }24
25    // Unlink the first node holding value26    static void delete(int value) {27        if (head == null) return;28        if (head.value == value) { head = head.next; return; }29        Node cur = head;30        while (cur.next != null && cur.next.value != value) cur = cur.next;31        if (cur.next != null) cur.next = cur.next.next;32    }33
34    static void print() {35        StringBuilder sb = new StringBuilder();36        for (Node cur = head; cur != null; cur = cur.next) {37            sb.append(cur.value).append(" -> ");38        }39        System.out.println(sb.append("null"));40    }41
42    public static void main(String[] args) {43        append(3); append(7); append(1); append(9);44        print();45        System.out.println("find 7: " + find(7));46        delete(7);47        print();48        System.out.println("find 7: " + find(7));49    }50}

1#include <iostream>2
3struct Node {4    int value;5    Node* next = nullptr;6    explicit Node(int v) : value(v) {}7};8
9struct LinkedList {10    Node* head = nullptr;11
12    void append(int value) {13        Node* node = new Node(value);14        if (head == nullptr) {15            head = node;16            return;17        }18        Node* cur = head;19        while (cur->next != nullptr) cur = cur->next;20        cur->next = node;21    }22
23    bool find(int value) const {24        for (Node* cur = head; cur != nullptr; cur = cur->next) {25            if (cur->value == value) return true;26        }27        return false;28    }29
30    void remove(int value) {31        if (head == nullptr) return;32        if (head->value == value) {  // removing the head is a special case33            Node* old = head;34            head = head->next;35            delete old;36            return;37        }38        for (Node* cur = head; cur->next != nullptr; cur = cur->next) {39            if (cur->next->value == value) {40                Node* old = cur->next;41                cur->next = old->next;42                delete old;43                return;44            }45        }46    }47
48    void print() const {49        for (Node* cur = head; cur != nullptr; cur = cur->next) {50            std::cout << cur->value << " -> ";51        }52        std::cout << "null\n";53    }54};55
56int main() {57    LinkedList list;58    for (int value : {10, 20, 30, 40}) list.append(value);59    list.print();60    std::cout << std::boolalpha << "find(30): " << list.find(30) << "\n";61    list.remove(20);62    list.remove(10);63    list.print();64    return 0;65}

1#include <stdbool.h>2#include <stdio.h>3#include <stdlib.h>4
5typedef struct Node {6    int value;7    struct Node* next;8} Node;9
10Node* head = NULL;11
12void append(int value) {13    Node* node = malloc(sizeof(Node));14    node->value = value;15    node->next = NULL;16    if (head == NULL) {17        head = node;18        return;19    }20    Node* cur = head;21    while (cur->next != NULL) cur = cur->next;22    cur->next = node;23}24
25bool find(int value) {26    for (Node* cur = head; cur != NULL; cur = cur->next) {27        if (cur->value == value) return true;28    }29    return false;30}31
32void deleteValue(int value) {33    if (head == NULL) return;34    if (head->value == value) {  // removing the head is a special case35        Node* old = head;36        head = head->next;37        free(old);38        return;39    }40    for (Node* cur = head; cur->next != NULL; cur = cur->next) {41        if (cur->next->value == value) {42            Node* old = cur->next;43            cur->next = old->next;44            free(old);45            return;46        }47    }48}49
50void printList(void) {51    for (Node* cur = head; cur != NULL; cur = cur->next) {52        printf("%d -> ", cur->value);53    }54    printf("NULL\n");55}56
57int main(void) {58    int values[] = {10, 20, 30, 40};59    for (int i = 0; i < 4; i++) append(values[i]);60    printList();61    printf("find(30): %s\n", find(30) ? "true" : "false");62    deleteValue(20);63    deleteValue(10);64    printList();65    return 0;66}