Arrays：練習題

Which of the following describes a key characteristic of an array in pseudocode as defined in the syllabus?

A two-dimensional (2D) array is declared as DECLARE \( Grid : \textbf{ARRAY}[1:4, 1:3] \) OF INTEGER. What is the total number of elements that can be stored in this array?

A 2D array Board[1:3, 1:3] is initialized with the value 0 in all elements. The following pseudocode is executed:

FOR R \(\leftarrow\) 1 TO 3
  FOR C \(\leftarrow\) 1 TO 3
    IF R < C THEN
      Board[R, C] \(\leftarrow\) 1
    ELSE
      Board[R, C] \(\leftarrow\) 2
    ENDIF
  NEXT C
NEXT R

What are the values of Board[1, 2] and Board[2, 1] respectively?

Which description best defines an array in programming as per the IGCSE syllabus?

An array Sales[1:4, 1:3] stores the following integers:
Row 1: 10, 20, 30
Row 2: 40, 50, 60
Row 3: 70, 80, 90
Row 4: 100, 110, 120

What is the result of the expression: \( Sales[2, 3] + Sales[4, 1] \)?

Write a pseudocode statement to declare a one-dimensional (1D) array named Temperatures that can store \( 7 \) real numbers.

Describe how a specific element is located and accessed within a two-dimensional (2D) array in pseudocode.

A 2D array Map[1:2, 1:3] contains the following data:
Row 1: \( 10, 20, 30 \)
Row 2: \( 40, 50, 60 \)

Identify the specific pseudocode index used to access the value \( 50 \) and explain why.

A software application needs to store the names of \( 20 \) different books in a library collection.

(a) Write a pseudocode statement to declare a one-dimensional (1D) array named BookTitles that can store these names.
(b) Write a single line of pseudocode to assign the string "Computer Science" to the last element of the array.

A teacher wants to record the marks for 5 students in a test. The marks should be stored in an array.

(a) Declare a one-dimensional array called StudentMarks that can store 5 integer marks.

(b) Write pseudocode to input 5 integer marks from the user and store them in the StudentMarks array.

(c) After all marks have been entered, calculate and output the average mark of the students, rounded to one decimal place.