Name the three main control structures used in algorithm development and give an example of each.
Design an algorithm to find the largest number in a list using iteration and selection.
When would you choose iteration over selection in an algorithm?
Write pseudo code to check if a number is even.
Write pseudo code to print numbers from 1 to 5 using a loop.
Answers and Descriptions
Answer: 1. Sequence: Executing statements in order (e.g., adding two numbers). 2. Selection: Making decisions (e.g., if a number is positive). 3. Iteration: Repeating steps (e.g., printing numbers 1 to 10).
Description: Control structures guide program flow. Sequence ensures linear execution, selection enables conditional branching, and iteration supports repetition, forming the core of algorithm design.Answer:
1 2 3 4 5 6 7 8 | INPUT list max = list[0] FOR each number IN list IF number > max THEN max = number ENDIF ENDFOR OUTPUT max |
Description: This algorithm uses iteration (looping through the list) and selection (comparing numbers) to find the maximum, demonstrating practical application of control structures.
Answer: Use iteration when repeating a task multiple times, such as summing numbers, and selection when making a one-time decision, like checking if a number is positive.
Description: Choosing the appropriate control structure depends on the problem. Iteration is ideal for repetitive tasks, while selection handles conditional logic, optimizing algorithm efficiency.Answer:
1 2 3 4 5 6 | INPUT number IF number MOD 2 = 0 THEN OUTPUT "Number is even" ELSE OUTPUT "Number is odd" ENDIF |
Description: Pseudo code provides a clear, human-readable algorithm representation. This example uses a selection structure to check divisibility by 2, reinforcing control structure application.
Answer:
1 2 3 | FOR i = 1 TO 5 OUTPUT i ENDFOR |
Description: A for loop is used when the number of iterations is known. This loop prints numbers 1 to 5, illustrating a basic iteration structure for repetitive tasks.