function hashPassword(password) {
    return crypto.createHash("sha256").update(password).digest("hex");
}

const express = require("express");
const bcrypt = require("bcrypt");
const mysql = require("mysql");

// 創(chuàng)建 MySQL 數(shù)據(jù)庫(kù)連接
const db = mysql.createConnection({
    host: "localhost",
    user: "root",
    password: "",
    database: "mydb",
});

// 連接數(shù)據(jù)庫(kù)
db.connect((err) => {
    if (err) {
        throw err;
    }
    console.log("MySQL connected...");
});

// 創(chuàng)建 express app
const app = express();

// 路由 handler
app.post("/login", (req, res) => {
    // get username and password from request body
    const { username, password } = req.body;

    // HASH 密碼
    const hashedPassword = bcrypt.hashSync(password, 10);

    // 在數(shù)據(jù)庫(kù)中查找用戶名稱
    let sql = `SELECT * FROM users WHERE username = '${username}'`;
    let query = db.query(sql, (err, result) => {
        if (err) throw err;

        // 檢查密碼是否匹配
        if (bcrypt.compareSync(result[0].password, hashedPassword)) {
            res.send("Login successful!");
        } else {
            res.send("Incorrect username or password");
        }
    });
});

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

// Structure for a node in the linked list
typedef struct Node {
    int identity; // Property of the node
    struct Node *next; // Pointer to the next node
} Node;
// Function to add a node to the linked list
void addNode(Node **head, int identity) {
    // Create a new node
    Node *newNode = (Node*)malloc(sizeof(Node));
    // Set the identity of the new node
    newNode->identity = identity;
    // Set the next pointer of the new node to point to the head
    newNode->next = *head;
    // Set the head to point to the new node
    *head = newNode;
}
// Function to delete a node from the linked list
void deleteNode(Node **head, int identity) {
    // Create a temporary node to traverse the linked list
    Node *temp = *head;
    // Check if the head is the node to be deleted
    if (temp != NULL && temp->identity == identity) {
        // Set the head to point to the next node
        *head = temp->next;
        // Free the memory allocated for the node
        free(temp);
        return;
    }
    // Traverse the linked list to find the node to be deleted
    while (temp != NULL && temp->identity != identity) {
        // Set the previous node to the current node
        Node *prev = temp;
        // Set the current node to the next node
        temp = temp->next;
    }
    // Check if the node was found
    if (temp == NULL) return;
    // Set the previous node to point to the next node
    prev->next = temp->next;
    // Free the memory allocated for the node
    free(temp);
}
// Function to find a node in the linked list
Node* findNode(Node *head, int identity) {
    // Create a temporary node to traverse the linked list
    Node *temp = head;
    // Traverse the linked list to find the node
    while (temp != NULL) {
        // Check if the current node has the given identity
        if (temp->identity == identity) {
            return temp;
        }
        // Set the current node to the next node
        temp = temp->next;
    }
    // Return NULL if the node was not found
    return NULL;
}
int main() {
    // Create a head node for the linked list
    Node *head = NULL;
    // Add some nodes to the linked list
    addNode(&head, 1);
    addNode(&head, 2);
    addNode(&head, 3);
    // Find a node in the linked list
    Node *node = findNode(head, 2);
    // Print the identity of the node
    printf("Node with identity 2: %d\n", node->identity);
    // Delete a node from the linked list
    deleteNode(&head, 2);
    // Find the deleted node in the linked list
    node = findNode(head, 2);
    // Check if the node was deleted
    if (node == NULL) {
        printf("Node with identity 2 was deleted\n");
    }
    return 0;
}