lesson 1 introduction

Lesson 1

Introduction

Introduction to Computer and Program Design

James C.C. Cheng

Department of Computer Science

National Chiao Tung University

About Me 鄭昌杰 Cheng, Chang-Chieh

Ph.D. Candidate, department of Computer Science, NCTU Email:

[email protected] Office:

交通大學新竹光復校區電資大樓 704 室 (Room 704, MISRC, NCTU)

Tel: 03-5712121 # 59268

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Syllabus

Introduction

C language overview

Data Types and Variables

Operators and Expressions

Statements

Pointers, Arrays and Memory Management

Functions

Standard I/O

String processing

Custom data type

Scoring

期中考 ( 筆試 ) 25%

期末考 ( 筆試 ) 25%

上機考 25%

平時作業 ( 含上課狀況 ) 25%

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Why should I take this course?

Every thing is computer

To learn the programming technique, because you can design a valuable and interesting computer program

the number of experiment results could be very large.

you have to control the instruments by computer

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Why should I learn the C and C++

For basic computer concepts learning

To design a high performance program

Windows programming GUI (graphical user interface) application software

Mobile software development iPhone, iPad iOS applications (apps)

Xcode with C++ or Objective C

Android applications GUI JAVA

Kernel C++

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Textbooks

C How to program, 6ed By P.J. Deitel & H.M. Deitel

Publisher: Prentice Hall

Features: Chapter 1: Introduction to computers

Plenty exercises

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Textbooks

The C programming Language, 2ed Authors: Brian W. Kernighan and Dennis M. Ritchie

Publisher: Prentice Hall

Features: Introduction to the C language

The first book on C language

Authors are the creators of C

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Textbooks

C++ Primer, 4ed By Stanley B. Lippman,

Josée Lajoie, Barbara E. Moo

Publisher:

Addison Wesley

Features: Introduction to OOP

中譯本 : 侯捷譯碁峰出版

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Reference Books

Thinking in C++ Volume 1 & Volume 2 , 2ed by Bruce Eckel, Chuck Allison

Free Electronic Book, http://www.mindviewinc.com/Index.php

Features: C++ and OOP 的進階書

中譯本蔡明志譯碁峰出版

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Reference Books

The C++ Standard Library - A Tutorial and Reference By Nicolai M. Josuttis

Publisher: Addison-Wesley

Feature: STL tool book

中譯本 : C++ 標準程式庫侯捷，孟岩譯碁峰出版

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Internet Resources

MSDN, Microsoft Developer Network http://msdn.microsoft.com/

Cplusplus.com http://www.cplusplus.com/

C++ wiki Link:

http://www.cppreference.com/wiki/ chm version:

http://www.cppreference.com/wiki/_media/about/

cppreferencecom_feb09.zip

Google, Yahoo and programming forums (PTT/Programming)

What is a computer?

A machine designed to solve some problem.

A programmable machine It can execute a sequence of instructions

Mostly, it is a digital system 二進位系統 ( binary system):

0/1, true/false, turn on/turn off.

It has data storage devices 非揮發性資料儲存裝置 Non-volatile data storage devices :

Punched cards, magnetic tapes, magnetic disks, optical disk, ROM

揮發性資料儲存裝置 Volatile data storage devices: Transistors, registers, memory, RAM, SDRAM, DDR

A communication device I/O ports, RS-232, LPT, IDE, SATA, USB

Ethernet, Internet

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Computer Organization

All computers consist of six components

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Computer Organization The motherboard of ?

Memory256 MB XDR

CPU:Cell Processor PowerPC-base Core 3.2GHz with Northbridge = Memory controller

GPU(Graphics Processing Unit):RSX 550MHz

I/O: USB,Sound, …

Southbridge = I/O controller

圖片來源 : Wikipedia

Computer Organization Desktop motherboard: ASUS P8P67

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I/O: USB, Sound, Network cable …

CPU socketIntel i7/i5 (LGA1155)

Memory socket

Power socketSATA sockets

PCI slots PCIe slots

Power socket for CPU

圖片來源 : ASUS

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Computer Organization

Memory access

CPUMemory

Address bus

Data bus

Bus: A bundle of electronic signal wires. In 32-bit computer, the bus consists of 32 wires In 64-bit computer, the bus consists of 64 wires

Quiz

找一台桌上型電腦 (desktop), 你能說出每一個開關、燈號、插孔及各裝置的名稱 ( 中英文 ) 及用途嗎 ?

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What is programming? 設計一連串的命令與符號讓電腦去解決某些問題

所設計的一連串命令與符號稱為原始碼 (Source code)

Machine code 機器碼以 0 及 1 兩種符號所構成的數碼原始碼必須被翻譯 (compile) 成機器碼才可讓電腦執行 Program language 程式語言設計原始碼所必須遵守的規則及語法較著名的程式語言 ( 從低階 ( low-level) 到高階 ( high-level)):

Assembly

C

C++

JAVA

Delphi (Pascal)

Microsoft Basic

SQL

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Programming Flow

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C++ IDE

Dev C++ http://www.bloodshed.net/devcpp.html

GCC-based compiler GCC: GNU Compiler Collection

原始碼有開放下載 (Open source), 不佔硬碟空間且免費它的原始碼編輯器 (editor) 及除錯器 (debugger) 有很多缺失

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C++ IDE

Code::Blocks http://www.codeblocks.org/

Multiple compiler support: GCC (MingW / GNU GCC)

MSVC++

...and more

原始碼有開放下載 (Open source), 不佔硬碟空間且免費有出各種平台版本除錯器 (debugger) 過於複雜難用

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C++ IDE

Visual Studio 不只有 C++ 還包含了 Visual Basic, C# and J#.

它的 C++ compiler 是微軟自己發明的 MS C++

在 v6.0 之前 , VS 使用 MFC (Microsoft Foundation Classes) 來建立視窗用程式 .

MFC: 問題缺失非常多的一個函式庫 !

VS 7.0~ use the .NET Framework.

Visual Studio Express: 免費精簡版，但已足夠開發一般的視窗程式

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C++ IDE

Embarcadero C++ Builder XE2 (2011) Based on Turbo C++ (1991~2006)

History Borland C++ Builder (1997~2006)

CodeGear C++ Builder (2006~2008)

Embarcadero C++ Builder (2008~)

用來開發Ｗ indows 級 MacOS X 的視窗程式

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C++ IDE

QT http://qt.nokia.com/products/

Based on MinGW (Minimalist GNU for Windows)

在歐洲及中國大陸非常流行免費用來開發各種平台的視窗程式 (source code cross-platform)

Microsoft Windows

X-Windows

Mac OS

iOS

Android

The History of the C Language

C language is created by Dennis Ritchie between 1969 -1972 1989, ANSI C89

1990, ISO C90 C89 C90 (C89 = C90)

1999, C99

2011, C11

C89 is the main development tool in the most embedded systems

Because C89 is simple, light weight, and high efficient

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ANSI: American National Standards Institute

ISO: International Organization for Standardization

Dennis Ritchie 1941-2011

圖片來源 : Wikipedia

The History of the C++ Language

1979, Bjarne Stroustrup develops the “C with Classes” language C language with object-oriented programming

1983, the “C with Classes” the C++ language

1998, 1st standard version: C++98

2003, 2nd standard version: C++03

2011, 3rd standard version: C++11

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Programming and Coding 一段簡單的 C 程式

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#include <stdlib.h> #include <stdio.h> int main(){ int x = 0; scanf("%d", &x); x = 1 + 2 * 3 / 4; printf ("%d\n", x); system("pause"); return 0;}

Programming and Coding 一段簡單的 C 程式，加上註解

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#include <stdlib.h> // 將 stdlib.h 裡面的內容複製貼上在這裡#include <stdio.h> // 將 stdin.h 裡面的內容複製貼上在這裡/* C89-style 區塊註解 . 請少用 C89 區塊註解 ! Why? */int main() /* 函數宣告式 :

return_type function_name ( arguments_list ) */{ //main 函數從這左大括號開始 int x = 0; // 變數宣告式 scanf("%d", &x); // scanf: 將資料從至標準輸入裝置 (standard input device) 讀取出來的函數 x = 1 + 2 * 3 / 4; // 將 1 + 2 * 3 / 4 的結果寫到 x 裡 printf ("%d\n", x); // printf: 將資料輸出至標準輸出裝置 (standard output device) 的函數 system("pause"); // 暫停指令，注意 ! 只有微軟的環境下才能使用 return 0; /* 告訴作業系統此程式將正常結束 */}

Programming and Coding

#include directive( 指令 ) 將所指定的檔案內容複製貼上 #include <SourceFile>

The path of SourceFile is

Default_Include_Path/SourceFile

The setting of Default_Include_Path

Tools / Compiler Options / Directories / C includes

#include “SourceFile“ Compiler searches the SourceFile if it is an absolute path

Compiler searches the SourceFile in the current directory if SourceFile is just

a filename

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Comments Single line comment //

c89 block comment /* */

c89 block comment 常如此誤用 :

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#include <stdlib.h>#include <stdio.h> int main(){

/* int x; /* x = 1 + 2 * 3 / 4; printf ("%d\n", x); */ printf ("Bye!\n", x);*/ system("pause"); return 0;

}


更好用的 block comment

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#include <stdlib.h>#include <stdio.h> int main() {

#if 0 int x; #if 0 x = 1 + 2 * 3 / 4; printf ("%d\n", x); #endif printf ("Bye!\n", x); #endifsystem("pause"); return 0;

}


The main function 所 C 程式的主要起始點 main function 是唯一的 . 千萬不可寫兩個 main function 在同一支程式 (

即使他們的 return type 及 and the arguments list 不相同 )

Simple type of the main function:

Complete types of the main function:

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int main( ) {

…}

int main( void ) { // void means empty …

}

int main( int argc, char *argv[ ] ) { … } // For UNIX

Programming and Coding 變數 Variables

在記憶體佔有一席之地，用來存放資料以便進行各種運算。變數使用前一定要被宣告 : 告訴編譯器 (compiler) 你要使甚麼樣的變數一即為這

變數取一個名字。

變數的宣告 Ex:

千萬不可以有兩個變數取相同名稱

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int x; // Declare an integerfloat y; // Declare a 32-bit floating-point numberdouble z; // Declare a 64-bit floating-point numberunsigned integer i; // Declare an unsigned integerchar c; // Declare a 8-bit characterchar S[100]; // Declare a 100 characters text string

int x; // Declare an integerint x; // Error! Redeclaration of x!float x; // Error! Redeclaration of x!


變數的宣告同時宣告多個同種類的變數 Multiple variables declaration:

宣告同時初始化 (initialization)

強烈建議所有變數在宣告同時也給初始值

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int a, b ,c; // Declare three integersfloat x, y, z, w; // Declare four 32bit floating-point numbers

int a = 0, b = 1, c;// a = 0 and b = 1 but c = ?

float x = 1.2f, y, z, w = 1.0f;// x = 1.2 and w = 1.0 but y and z = ?// 1.2f means 1.2 is a 32-bit floating-point number// 1.2 means 1.2 is a 64-bit floating-point number

Char S[100] = {0}; // All characters are zero


Statements and Expressions 運算式 Expressions

一個運算式是由變數 (variables), 常數 (constants), 運算子 (operators) 及函數呼叫 (function calls) 所組成

任何運算式皆會算出一個值 (value).

敘述 Statements 一句敘述是由符號 (tokens), 運算式 (expressions), 及其他敘述句所組成 .

以分號 (;) 左為敘述句的結尾

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int x; // A declaration statement

x = 1 + 2 * 3 / 4; /* An assignment statement 1+2*3/ 4 is an expression */

x = printf("Hello\n"); /*An assignment statement printf("Hello\n"); is an expression */


左值 (L-value) 與右值 (R-value) 非常重要的觀念 ! 左值 L-value: 可以放在等號的左邊

一定是一個變數因為變數在記憶體裡佔有一席之地一定代表著可以寫入資料的記憶體空間常數 constant 不可以當左值

右值 R-value: 可以放在等號的右邊任何可提供數值的符號 ( 變數或常數 )都可以當右值 , 但是要注意左值與右值

的型態是否匹配

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int x, y;x = 1 + 2 * 3 / 4; // x: L-value; 1+2*3/4: R-valuey = x; // y: L-value; x: R-value 1+2*3/4 = y; // error! 1+2*3/4 cannot be a L-valuex+1 = y; // error! x+1 cannot be a L-valueint *p; // p 是一種專門存放某個 int 變數的記憶體位址

// p 也是一種變數 , 這種專門放位址的變數我們稱為指位器 (pointer)p = x; // error! p 與 x型態不匹配

C/C++ Operators - 1

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Precedence Operator Description Associativity

1(highest) :: Scope resolution (C++ only) Left-to-right

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++ Suffix increment-- Suffix decrement() Function call[] Array subscripting. Element selection by reference-> Element selection through pointertypeid() Run-time type information (C++ only) const_cast Type cast (C++ only) dynamic_cast Type cast (C++ only)reinterpret_cast Type cast (C++ only)static_cast Type cast (C++ only)

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++ Prefix increment Right-to-left-- Prefix decrement+ Unary plus- Unary minus! Logical NOT~ Bitwise NOT(type) Type cast* Indirection (dereference)& Address-ofsizeof Size-ofnew, new[] Dynamic memory allocation (C++ only)

delete, delete[] Dynamic memory deallocation (C++ only)

(listed by Wikipedia)

C/C++ Operators - 2

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4.* Pointer to member (C++ only) Left-to-right->* Pointer to member (C++ only)

5* Multiplication/ Division% Modulo (remainder)

6+ Addition- Subtraction

7<< Bitwise left shift>> Bitwise right shift

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< Less than<= Less than or equal to> Greater than>= Greater than or equal to

9== Equal to!= Not equal to

10 & Bitwise AND11 ^ Bitwise XOR (exclusive or)12 | Bitwise OR (inclusive or)13 && Logical AND14 || Logical OR



15 ?: Ternary conditional (see ?:) Right-to-left

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= Direct assignment

+= Assignment by sum

-= Assignment by difference

*= Assignment by product

/= Assignment by quotient

%= Assignment by remainder

<<= Assignment by bitwise left shift

>>= Assignment by bitwise right shift

&= Assignment by bitwise AND

^= Assignment by bitwise XOR

|= Assignment by bitwise OR

17 throw Throw operator (exceptions throwing, C++ only) 　18 , Comma Left-to-right

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C/C++ Operators - 3



函數的規格 The specification of a function Return_Type FunctionName(argument1, argument2, …. );

Ex : int getchar( void );

int printf( const char *format [, argument]... );

函數的呼叫 Function calling Syntax:

Function_Name( )

Function_Name( argument1, argument2, …. )

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int x = getchar(); // Call getchar without argument to obtain an input characterprintf(“%d\n“, x); // Call printf with two arguments to display the value of x

scanf & printf

scanf: 標準輸入函數 ; printf: 標準輸出函數使用前都要 #include <stdio.h>

第一個參數是必要的，而且是一個字串，代表輸入 / 出的格式第二個之後的參數都是選項，代表輸入 / 出的資料往後我們會再詳細的介紹這兩個 function

example：

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int x = 0, y = 0, z = 0;scanf("%d", &x);scanf("%d %d", &y, &z);printf("%d, %d, %d\n", x, y, z);

scanf("%d%d%d", &x, &y, &z);printf("%d", x);printf("%d\t\n%d\n", y, z);

%d: 依照順序抓後面的參數，並以十進位整數來處理

& 變數名稱 : 取出變數在記憶體的位址

\n: new line 換行\t: tab

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條件敘述 Condition Statements

if then else

Be careful for the declaration statements in block

int x = 10;if(x == 1) printf("x is 1\n");else printf("x is not 1\n");

// this line will be executedif(x = 1) printf("x is 1\n"); // this line will be executed, why?else printf("x is not 1\n");

int n;scanf("%d", &n); if(n >= 0){ int n = n; // An undefined behavior printf("%d is positive\n", n); }else printf("%d is negative\n", n);

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if … then … else … Do not write such condition expression

if( 0<= x < 10 ) if( (0<=x) && (x < 10) )

It will always be true. Why?

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if … then … else …

if(…){

…

}

else{

if(…){

…

}

else{

…

}

}

if(…){

…

}

else if(…){

…

}

else{

…

}

if(…){

…

}

else if(…){

…

}else{ …}

else{ // Error!

…

}

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重複性敘述 Iteration Statements

重複性敘述代表這種敘述句會重複執行數次 C++ 有三種重複性敘述

while (expression){ … } do { … } while (expression); for (s-expression; expression; n-expression) { … }

迴圈結束條件 loop-termination criteria The r-value of expression is false break

continue The continue statement ignore the rest statements and passes control

to the next iteration

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重複性敘述 Iteration Statements

Compare these three cases:

int n = 0, s = 0;scanf("%d", &n);while(n!=0){ s = s + n; n = n – 1;}printf("%d\n", s);

int n = 0, s = 0;scanf("%d", &n);do{ s = s + n; n = n – 1;} while(n != 0);printf("%d\n", s);

int n = 0, s = 0;int i = 0;scanf("%d", &n);for(i=1; i<=n; ++i) s = s + i;printf("%d\n", s);

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Compiler’s Warnings & Errors

警告訊息 Warning messages Warning 不會中斷編譯工作 .

Warning 可以被忽略 .

int x = 1.0; warning C4244: '=' : conversion from 'double' to 'int',

但是有些 Warning 不可以被忽略int x = -1;

unsigned int y = 0;

if( x > y) printf("%d > %d", x, y);

warning C4018: '>' : signed/unsigned mismatch

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Compiler’s Warnings & Errors

錯誤訊息 error messages 錯誤訊息會中斷編譯工作 .

錯誤訊息你必須去解決它 . x = 1 + 1 // syntax error : missing ';‘

if( x<0){

x = 100;

// fatal error : without right brace ‘}'

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Bugs

What is a bug? 就是程式上的執行錯誤及瑕疵早期的計算機由於體積非常龐大，有些小蟲子可能會鑽入機器內部，造

成計算機工作失靈。因此用「 Bug」來稱之。例如 :

文法上錯誤 Lexical error

連結失敗 Linking failed

使用到位初始化的變數 Uninitiated variable

除以零 Divided by zero

使用作業系統的資源造成的錯誤 System error

邏輯上的錯誤 Logical error

Debugging in Dev C++ Breakpoint

An stopping or pausing place in a program

Set a breakpoint in Dev C++

Press Ctrl + F5 or by clicking in front of the line, outside of the editor window

Debug mode Debug / Debug or press F8

Start to run your program

Stop on the first breakpoint line. Notice that the breakpoint line not be executed

yet.

Continue to the next line:

Debug / Next Step or press F7

Continue to the next breakpoint

Debug / Continue or press Ctrl + F7

Stop the execution:

Debug / Stop Execution or press Ctrl + Alt + F2

The code must be recompiled if the code has been modified

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Debugging in Dev C++ How to monitor the variables?

Put the mouse icon on the variable for a while

Or mark the variable, right click on it and click the Add Watch

Or press F4 then type the name of the variable

The value of the variable will be shown on the debug window, the left

side of the code editor.

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練習題1. 台灣有四種硬幣： 1元、 5元、 10元、 50元。請寫一個程式，讓使用者可以輸入一個正整數，並算出最佳的硬幣組合。例：輸入 136 ，則會算出 1 個 1元、 1 個 5元、 3 個 10元、 2 個 50元

2. 請寫一個程式，讓使用者可以輸入一個十進位正整數，並加總所有位數 (digit)。 1. 本題禁止用字串處理方式，輸入數字部分只能用 scanf("%d", &n);。2. 例 : 輸入 8051 ，則會顯示 8+0+5+1 = 14

3. 費伯納西數列 (Fibonacci number) F0 = 1, F1 = 1

Fn = Fn-1 + Fn-2 if n > 1

請寫一個程式，讓使用者可以輸入一個正整數 n。再個別以while ， do…while ，及 for loop 這三種重複性敘述來產生 F0~Fn 的費伯納西數

例 : 輸入 12 ，則會顯示三次下列結果 ( 用三種不同的重複性敘述 )

0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144

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lesson 1 introduction

Documents