程序流程图和伪代码
实验二：程序流程图和伪代码¶
实验目的：当大家学习了程序的控制结构之后，代码就变得复杂起来。在这时，我们解决问题就需要有很严密的逻辑思维。程序流程图和伪代码就是帮助我们去描述我们解决问题的方法（也称为算法）的工具。本次实验在于让大家学习如何使用这些工具，这对大家以后的编程有很大的帮助。
1.Flowchart(程序流程图)¶
A flowchart is a type of diagram that represents an algorithm, workflow or process, showing the steps as boxes of various kinds, and their order by connecting them with arrows. This diagrammatic representation illustrates a solution model to a given problem. Flowcharts are used in analyzing, designing, documenting or managing a process or program in various fields.
From wikipedia
Detailed Description: flowchat
There is an example:
And this is the flowchart:
2.Pseudocode (伪代码)¶
Pseudocode is an informal high-level description of the operating principle of a computer program or other algorithm.
From wikipedia
There is an example:
We can describe this question by this way rather than write a C program immediately:
main { input two integers height and n initialize answer = 0 loop for n times { input tree_height if height >= tree_height: answer = answer + 1 } print answer }
Pseudocode is used to express your thought, you do not need to care about the grammar.
Pre Assignment¶
Learn about Flowchart and Pseudocode.
Assignment 0 (20pts)¶
Choose one question from soj.me in week6 in our course and then write the Pseudocode.
Assignment 1 (35pts)¶
option 1¶
Translate the following flowchart into Pseudocode
option 2¶
Translate the following flowchart into Pseudocode and C programming language program.
Description¶
Several surveys indicate that the taller you are, the higher you can climb the corporate ladder. At TALL Enterprises Inc. this "de facto standard" has been properly formalized: your boss is always at least as tall as you are. Furthermore, you can safely assume that your boss earns a bit more than you do. In fact, you can be absolutely sure that your immediate boss is the person who earns the least among all the employees that earn more than you and are at least as tall as you are. Furthermore, if you are the immediate boss of someone, that person is your subordinate, and all his subordinates are your subordinates as well. If you are nobody's boss, then you have no subordinates. As simple as these rules are, many people working for TALL are unsure of to whom they should be turning in their weekly progress report and how many subordinates they have. Write a program that will help in determining for any employee who the immediate boss of that employee is and how many subordinates they have. Quality Assurance at TALL have devised a series of tests to ensure that your program is correct. These test are described below.
May be you can not write out the problem, the only work you will do is write out this program from the following flowchart(Since there are many methods to sort, so you can use one of them, the flowchart does not display in the flow chat, instead a dashed line).
Flowchart¶
Simple input and output¶
Input¶
2 3 123456 14323 1700000 123458 41412 1900000 123457 15221 1800000 123458 4 200002 12234 1832001 200003 15002 1745201 200004 18745 1883410 200001 24834 1921313 200002
Output¶
(0,2) (200004,0)
Assignment 2 (35pts)¶
Draw a flowchart from the following C language program which instruct the movement of a robot going on patrol along the wall.
#include <stdio.h>
/* this program is used for a robot to walk along
a wall next to him.
*/
/* Note that if the robot's eyes get something
whose distance is less than 40cm, there must
be an obstacle(wall).
*/
const int SENSOR_DISTANCE = 40; // 40 cm
/*
predifined methods:
1. void lookLeft() and void lookRight()
function: Let the robot to look at the left or right side.
2. void lookForward()
function: let the robot to look forward.
3. int getDistance()
function: get a distance from the eye to another.
object if there is one.
4. void moveStraight()
function: go straight for some distance.
5.int shutDown()
function: shut down the robot.
*/
int main() {
/* we assume that for the initial state, either
the robot's left side or the right side is
toward the wall.
wall = 0 means that the wall is at the left side
wall = 1 means that the wall is at the right side
*/
int wall;
lookLeft();
if(getDistance() < SENSOR_DISTANCE) {
wall = 0;
} else {
lookRight();
wall = 1;
}
if(wall == 0) {
while(shutDown() != 1) {
moveStraight();
while(1) {
lookLeft();
if(getDistance() < SENSOR_DISTANCE) {
lookForward();
if(getDistance() < SENSOR_DISTANCE) {
turnRight();
} else {
break;
}
} else {
turnLeft();
}
}
}
} else {
do {
moveStraight();
while(1) {
lookRight();
if(getDistance() < SENSOR_DISTANCE) {
lookForward();
if(getDistance() < SENSOR_DISTANCE) {
turnLeft();
} else {
break;
}
} else {
turnRight();
}
}
} while (shutDown() != 1);
}
return 0;
}
Extended Assignment (10pts)¶
option 1¶
Draw a flowchart and write Pseudocode as well as a C language program for the following description.
option 2¶
Simplify the logic in Assignment 2 and then draw a new flowchart and rewrite the C code.（Reduce at least one level of logic nesting）
Discussion，Cooperation and Summary (15pts)¶
In this part, you will have some options, if you do more options, you will learn more and get more marks. You should note this part in your report
option 1: Github Discussion¶
Comment at this issue and decribe a problem that you meet and how you solve detailedly.
Notice that 1. you should not copy and paste your personal report simply. 2. you should not write a very simple one and your comment will be deleted if you do that. 3. you should not post meaningless questions.
option 2: Simple Presentation¶
Have a simple presentation in the lab class on Monday (4 persons limited). And after the presentation, everyone is encouraged to ask questions and you can get bonus by asking good questions.
Notice that 1. The presentation is no more than 5 minutes and there will be 5 extra minutes for discussion. 2. You should prepare much for it. 3. First come, first get the opportunity.
option 3: Helping others¶
You can help others to slove any problems the will meet. Detailedly decribe the quesion, the solution and your personal experience as well.
Notice that 1. it's no need to consult with others that I help you, you help you to get marks. You can simply send email to me and I will give you the marks.
option 4: Personal Summary¶
Write personal summary for yourself. List at least 10 problems that you have met in your learning in c language and decribe the solution as well.
Notice that 1. you should not have ten very simple problems, you must let me know your learning method and also the method to solve problems.
Report(50% pts for your project ducumenting):¶
There will be no Report Template this time which means it's all depends on yourself.
Notice that 1. the report is the most important document for your project, you should pay more attention to it. 2. you are supposed to write a report that is friendly to your 'users', which means that you need to consider about the typesetting, the logical structure of the content. 3. There should contain one item, self grading that you should give a score to evaluate your job as well as a reason.
For example: sinew
Flowchart Tool: Process On¶
Process on is a good tool for drawing flowchart. link
Submit List¶
Notice that: 13331314 means your student id. the first assignment need to name your file with your chosen problem id.
Deadline and how to submit:¶
18:00 on Nov 7th, 2015
学习委员整理好发到邮箱：423093883@qq.com 不接受作业单独发到邮箱
Notification:¶
- Submit after deadline will cause a 30% penalty.
- If your file structure of filename is wrong, you will probably get 0 in that part.
- Any questions, you can ask us and email is better.
- Full mark will be 100, but you may get more than 100 within this project.
- You can use any tool include word, process on to draw a flowchart. You can use any form to write your Pseudocode but should be of high readability. If TA can not understand your Pseudocode clearly, you will get low points.(you can use Chinese to write Pseudocode if you like).