Constructs：練習題

Which programming construct is used to repeat a block of code a specific number of times?

Consider the following pseudocode snippet:

x = 10
y = 5
IF x > y THEN
  x = x - y
ELSE
  y = y - x
ENDIF

Which programming construct is demonstrated by the IF statement?

Which of the following is a characteristic of a subprogram (procedure or function) that uses a single entry point and a single exit point?

Which programming construct is used to execute a set of instructions multiple times until a specific condition is no longer met?

In a high-level programming language, which of the following best describes the use of a local variable within a subprogram?

Identify the programming construct used to execute a block of code only if a specific condition is met.

Describe the difference between a count-controlled loop and a condition-controlled loop.

Explain the benefit of using local variables within a subprogram instead of global variables.

A algorithm is designed to calculate the factorial of a number \(n\) (written as \(n!\)).

(a) Use pseudocode to write a count-controlled loop that calculates \(5!\) and stores it in a variable result.
(b) Explain why a condition-controlled loop (like a WHILE loop) might be used instead if the user was providing the input value.
(c) How would you modify the algorithm to ensure it doesn't crash if the user enters a negative number?