2043. Simple Bank System

Leetcode link

题目简介

这是一道系统设计题

题目回调用我们的构造函数 Bank 并且传入一个数字数组 balance，其长度为账户的数量，数组内的元素代表该帐号的余额

题目要求我们实现一系列的操作：

• transfer：将 account1 账户的 money 转账到 account2 账户
• deposit：将 money 存入 account 账户
• withdraw：从 account 账户取出 money

解题思路

只需要注意这些操作失败的原因有两个：

1. 该帐号不存在：account > balance.length
2. 该帐号转出的钱比当前存款多：money > balance[account - 1]

Javascript

/**
 * @param {number[]} balance
 */
var Bank = function (balance) {
    this.balance = balance
    this.len = balance.length
};

/** 
 * @param {number} account1 
 * @param {number} account2 
 * @param {number} money
 * @return {boolean}
 */
Bank.prototype.transfer = function (account1, account2, money) {
    if (account1 > this.len || account2 > this.len || this.balance[account1 - 1] < money) {
        return false
    }
    this.balance[account1 - 1] -= money
    this.balance[account2 - 1] += money
    return true
};

/** 
 * @param {number} account 
 * @param {number} money
 * @return {boolean}
 */
Bank.prototype.deposit = function (account, money) {
    if (account > this.len) {
        return false
    }
    this.balance[account - 1] += money
    return true
};

/** 
 * @param {number} account 
 * @param {number} money
 * @return {boolean}
 */
Bank.prototype.withdraw = function (account, money) {
    if (account > this.len || this.balance[account - 1] < money) {
        return false
    }
    this.balance[account - 1] -= money
    return true
};

/** 
 * Your Bank object will be instantiated and called as such:
 * var obj = new Bank(balance)
 * var param_1 = obj.transfer(account1,account2,money)
 * var param_2 = obj.deposit(account,money)
 * var param_3 = obj.withdraw(account,money)
 */