54_于宏学_第一课作业

Lesson-1/assignment/yours.sol

@@ -1 +1,65 @@
 /*作业请提交在这个目录下*/
+pragma solidity ^0.4.14;
+
+contract Payroll {
+
+    uint constant payDuration = 10 seconds;
+    address owner;
+    uint salary;
+    address employee;
+    uint lastPayday;
+
+    function setAddress(address _address){
+        employee=_address;
+    }
+    function setSalary(uint _salary){
+        salary = _salary;
+    }
+
+    function getAddress() constant returns(address){
+        return employee;
+    }
+
+    function getSalary() constant returns(uint){
+        return salary;
+    }
+
+    function Payroll() {
+        owner = msg.sender;
+    }
+
+    function updateEmployee(address e, uint s) {
+        require(msg.sender == owner);
+
+        if (employee != 0x0) {
+            uint payment = salary * (now - lastPayday) / payDuration;
+            employee.transfer(payment);
+        }
+
+        employee = e;
+        salary = s * 1 ether;
+        lastPayday = now;
+    }
+
+    function addFund() payable returns (uint) {
+        return this.balance;
+    }
+
+    function calculateRunway() returns (uint) {
+        return this.balance / salary;
+    }
+
+    function hasEnoughFund() returns (bool) {
+        return calculateRunway() > 0;
+    }
+
+    function getPaid() {
+        require(msg.sender == employee);
+
+        uint nextPayday = lastPayday + payDuration;
+        assert(nextPayday < now);
+
+        lastPayday = nextPayday;
+        employee.transfer(salary);
+    }
+}

Lesson-2/README.md

@@ -0,0 +1,16 @@
+## 硅谷live以太坊智能合约频道官方地址
+
+### 第二课《智能合约设计进阶-多员工薪酬系统》
+
+目录结构
+  <br/>|
+  <br/>|--orgin 课程初始代码
+  <br/>|
+  <br/>|--assignment 课程作业提交代码
+<br/> 
+### 本节知识点
+第2课：智能合约设计进阶-多员工薪酬系统
+- 动态静态数组的不同
+- 函数输入参数检查 revert
+- 循环与遍历的安全性
+- 程序运行错误检查和容错：assert与require

Lesson-2/assignment/README.md

@@ -0,0 +1,10 @@
+## 硅谷live以太坊智能合约 第二课作业
+这里是同学提交作业的目录
+
+### 第二课：课后作业
+完成今天的智能合约添加100ETH到合约中
+- 加入十个员工，每个员工的薪水都是1ETH
+每次加入一个员工后调用calculateRunway这个函数，并且记录消耗的gas是多少？Gas变化么？如果有 为什么？
+- 如何优化calculateRunway这个函数来减少gas的消耗？
+提交：智能合约代码，gas变化的记录，calculateRunway函数的优化
+

Lesson-2/assignment/yours.sol

@@ -0,0 +1,109 @@
+/*作业请提交在这个目录下*/
+现在我的代码还有点问题，正在修改当中
+/*
+transact to Payroll.addEmployee errored: VM error: invalid opcode.
+invalid opcode	
+	The execution might have thrown.
+	Debug the transaction to get more information. 
+*/
+gas消费应该是增加的，因为每一次都会多执行for循环
+代码现在正在修改中ing
+
+pragma solidity ^0.4.14;
+contract Payroll{
+
+    struct Employee{
+        address id;
+        uint salary;
+        uint lastPayday;
+    }
+    uint constant payDuration  = 10 seconds;
+    address owner;
+
+    Employee[] employees;
+
+    //测试函数
+    function getEmployee()
+    {
+        for(uint i=0;i<employees.length;i++ ){
+            //return (employees[i],i);
+        }
+    }
+
+    //构造函数
+    function Payroll(){
+        owner = msg.sender;
+    }
+    //应付的ETH
+    function _partialPaid(Employee employee) private {
+        uint payment = employee.salary * (now-employee.lastPayday)/payDuration;
+        employee.id.transfer(payment);
+    }
+
+    //查找用户是否存在
+    function _findEmployee(address employee) private returns(Employee storage,uint)
+    {
+        for(uint i= 0; i< employees.length; i++){
+            if(employees[i].id == employee){
+                return (employees[i],i);
+            }
+
+        }
+    }
+    //添加用户
+    function addEmployee(address employeeId,uint salary)
+    {
+        require(msg.sender == owner);
+        var (employee,index) = _findEmployee(employeeId);
+        assert(employeeId == 0x0);
+        assert(index > 10);
+        employees.push(Employee(employeeId,salary,now));
+    }
+
+    //删除用户
+    function removeEmployee(address employeeId)
+    {
+        require(msg.sender == owner);
+        var (employee,index) = _findEmployee(employeeId);
+        assert(employeeId != 0x0);
+        _partialPaid(employees[index]);
+        delete employees[index];
+        employees[index] = employees[employees.length-1];
+        employees.length -=1;
+    }
+
+    //更新用户信息
+    function updateEmployee(address employeeId,uint salary){
+        require(msg.sender==owner);
+        var (employee,index) = _findEmployee(employeeId);
+        assert(employee.id != 0x0);
+        _partialPaid(employees[index]);
+        employees[index].salary = salary;
+        employees[index].lastPayday = now;
+    }
+
+    //能够支付多少薪水
+    function calculateRunway() returns(uint){
+        uint totalSalary = 0;
+        for(uint i= 0; i< employees.length; i++){
+            totalSalary+=employees[i].salary;
+        }
+        return this.balance/totalSalary;
+    }
+
+    //支付薪水
+    function getPaid()
+    {
+        var(employee,index) = _findEmployee(msg.sender);
+        assert(employee.id != 0x0);
+        uint nextPayday = employee.lastPayday+payDuration;
+        assert(nextPayday<now);
+        employees[index].lastPayday = nextPayday;
+        employees[index].id.transfer(employee.salary);
+    }
+    //合约中的ETH
+    function addFund() payable returns (uint) {
+        return this.balance;
+    }
+
+}

Lesson-2/orgin/README.md

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+## 硅谷live以太坊智能合约 第二课《智能合约设计进阶-多员工薪酬系统》
+
+这里是每一课的初始代码，有需要的同学可以参考

Lesson-2/orgin/payroll.sol

@@ -0,0 +1,50 @@
+pragma solidity ^0.4.14;
+
+contract Payroll {
+    struct Employee {
+        address id;
+        uint salary;
+        uint lastPayday;
+    }
+
+    uint constant payDuration = 10 seconds;
+
+    address owner;
+    Employee[] employees;
+
+    function Payroll() {
+        owner = msg.sender;
+    }
+
+    function _partialPaid(Employee employee) private {
+    }
+
+    function _findEmployee(address employeeId) private returns (Employee, uint) {
+    }
+
+    function addEmployee(address employeeId, uint salary) {
+    }
+
+    function removeEmployee(address employeeId) {
+    }
+
+    function updateEmployee(address employeeId, uint salary) {
+    }
+
+    function addFund() payable returns (uint) {
+    }
+
+    function calculateRunway() returns (uint) {
+        uint totalSalary = 0;
+       for (uint i = 0; i < employees.length; i++) {
+            totalSalary += employees[i].salary;
+        }
+        return this.balance / totalSalary;
+    }
+
+    function hasEnoughFund() returns (bool) {
+    }
+
+    function getPaid() {
+    }
+}