Computing notes
Chapter 1
- Computer science is the study of algorithms ,their formal and mathematical
properties, Their hardware realizations,Their linguistic realizations,&Their
applications
- Operations used to construct algorithms:
• Sequential operations: Carries out a single well-defined task
• Conditional operations: Ask a question and the next operation is then selected
on the basis of the answer to that questionI
• Iterative operations: Looping instructions that tell not to go on but go back and
repeat the execution of a previous block of instructions
- Why are formal algorithms so important in computer science?
• If we can specify an algorithm to solve a problem, then we can automate its
solution
- Computing agent: Machine, robot, person, or thing carrying out the steps of the
algorithm
- The Formal Definition of an Algorithm:
• A well-ordered collection of unambiguous and effectively computable
operations that, when executed, produces a result and halts in a finite amount
of time
- Computers developed from mechanical calculating devices to modern electronic
marvels of miniaturization.
Chapter 2
- How can an electronic (or magnetic) machine represent information?
• Key requirements: clear, unambiguous, and reliable
- External representation is human-oriented
• Base-10 numbers
• Keyboard characters
1
, - Internal representation is computer-oriented
• Base-2 numbers
• Base-2 codes for characters
- Binary is the simple idea of On/Off, Yes/No, True/False, and Positive/Negative.
- Binary is important to computing systems because of it’s stability and reliability.
- All data stored inside a computer is stored in binary (also called machine
language) and interpreted to display on the screen in human language.
- The binary numbering system is a base-2 positional numbering system
• Base ten:
- Uses 10 digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9
- Each place corresponds to a power of 10
- 1,943 = (1 × 103) + (9 × 102) + (4 × 101) + (3 × 100)
• Base two:
- Uses 2 digits: 0 and 1
- Each place corresponds to a power of 2
- 1101 = (1 × 23) + (1 × 22) + (0 × 21) + (1 × 20) = 13
2
Chapter 1
- Computer science is the study of algorithms ,their formal and mathematical
properties, Their hardware realizations,Their linguistic realizations,&Their
applications
- Operations used to construct algorithms:
• Sequential operations: Carries out a single well-defined task
• Conditional operations: Ask a question and the next operation is then selected
on the basis of the answer to that questionI
• Iterative operations: Looping instructions that tell not to go on but go back and
repeat the execution of a previous block of instructions
- Why are formal algorithms so important in computer science?
• If we can specify an algorithm to solve a problem, then we can automate its
solution
- Computing agent: Machine, robot, person, or thing carrying out the steps of the
algorithm
- The Formal Definition of an Algorithm:
• A well-ordered collection of unambiguous and effectively computable
operations that, when executed, produces a result and halts in a finite amount
of time
- Computers developed from mechanical calculating devices to modern electronic
marvels of miniaturization.
Chapter 2
- How can an electronic (or magnetic) machine represent information?
• Key requirements: clear, unambiguous, and reliable
- External representation is human-oriented
• Base-10 numbers
• Keyboard characters
1
, - Internal representation is computer-oriented
• Base-2 numbers
• Base-2 codes for characters
- Binary is the simple idea of On/Off, Yes/No, True/False, and Positive/Negative.
- Binary is important to computing systems because of it’s stability and reliability.
- All data stored inside a computer is stored in binary (also called machine
language) and interpreted to display on the screen in human language.
- The binary numbering system is a base-2 positional numbering system
• Base ten:
- Uses 10 digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9
- Each place corresponds to a power of 10
- 1,943 = (1 × 103) + (9 × 102) + (4 × 101) + (3 × 100)
• Base two:
- Uses 2 digits: 0 and 1
- Each place corresponds to a power of 2
- 1101 = (1 × 23) + (1 × 22) + (0 × 21) + (1 × 20) = 13
2
