Problem Solving Techniques Using Pascal

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Problem Solving Techniques Using Pascal

• Allen C.-H. Wu
• Department of Computer Science
• Tsing Hua University
• Hsinchu, Taiwan 30043, ROC
• email chunghaw_at_cs.nthu.edu.tw

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Chapter 1

• Overview Of Computers and Programming

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Overview
Do as I told you!
HOW?
Chips
Program
Software
Hardware
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A Computer System
Outputs
Inputs
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Interactions between the Users and Computer

• The user develops a program.
• The computer fetches the program and data through
  the input devices and stores them in the main
  memory.
• The data then be accessed and manipulated by the
  CPU.
• Finally, the results of this manipulation are fed
  back to the user via the output devices.

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Analogy to Human Systems

• A man/woman see a simple arithmetic problem
  (e.g., 11?) from the blackboard. gt Eyes are
  the input device.
• He/she stores the data into his/her brain.
  gt Brain cell memory cell.
• His/her brain computes 11 and stores the result
  of 2 into the brain cell.
• Finally, he/she tells you or writes down the
  answer. gt Mouth is the output device.

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Anatomy of Memory

• Address and contents of a memory cell.
• Stored program concept.
• Bytes and bits.
• Storage and retrieve of information in memory.
• Main memory (RAM and ROM).
• Secondary memory and storage devices.

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CPU and IO Devices

• The CPU has two roles (1) coordinating all
  computer operations and (2) performing arithmetic
  and logical operations on data.
• The CPU retrieves the instruction stored in
  memory in sequence.
• IO devices communicates users and computers.
• Computer networks and file servers.

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Human, Computer, Problem Solving
Solve
Describe or formulate
Solution
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Programming Strategy

• Plan your program solution.
• Desk check your solution plan (make changes to
  your solution).
• Write out your program.
• Desk check your program (makes changes to your
  program).
• Enter the program into the computer.

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Overview of Programming Languages

• Programming languages gt Programs.
• Machine languages gt string of 0s and 1s gt
  understand by the computer.
• High-level languages gt everyday languages gt
  understand by the users.
• Language standard gt grammar (syntax
  semantics).
• Source program gt object program.

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Processing a High-Level Language Program

• Editing a program.
• Compiling the program - syntax error checking.
• Linking and loading the object program and
  storing it in the memory for execution.
• Preparing the input file, executing the program,
  and output the results.

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Turbo Pascal

• Two common used operating systems (OS) Microsoft
  Disk Operating System (DOS) and Microsoft
  Windows (Windows).