Unit 3: Algorithms and Programming

What is the value of x after the following code segment is executed? x ← 5 x ← x + 3 x ← x * 2

What is the output of the following code segment? a ← 10 b ← 20 a ← b DISPLAY(a)

What are the values of a and b after the following code segment? a ← 3 b ← 7 temp ← a a ← b b ← temp

What is displayed by this code segment? nums ← [4, 7, 2, 9, 1] max ← nums[1] FOR EACH num IN nums { IF (num > max) { max ← num } } DISPLAY(max)

What is displayed after executing this code? result ← 0 FOR i ← 1 TO 5 { result ← result + i } DISPLAY(result)

A list contains n elements. A linear search is used to find a specific value. What is the maximum number of comparisons needed?

A sorted list contains 1024 elements. Using a binary search, what is the maximum number of comparisons needed to find a specific value?

Which of the following is a key requirement for binary search to work correctly?

What is displayed by the following code? PROCEDURE double(x) { RETURN x * 2 } result ← double(double(3)) DISPLAY(result)

Which algorithm has a reasonable (polynomial) running time?

What is displayed by the following code? list ← [1, 2, 3, 4, 5] FOR EACH item IN list { IF (item MOD 2 = 0) { DISPLAY(item) } }

What is the output of the following code? list ← [3, 1, 4, 1, 5] n ← LENGTH(list) FOR i ← 1 TO n - 1 { IF (list[i] > list[i + 1]) { temp ← list[i] list[i] ← list[i + 1] list[i + 1] ← temp } } DISPLAY(list)

What is displayed by the following code? PROCEDURE mystery(a, b) { IF (a > b) { RETURN a } ELSE { RETURN b } } DISPLAY(mystery(mystery(3, 5), mystery(4, 2)))

An algorithm is designed to work on a list of n items. Which of the following running times would be considered "unreasonable" for large values of n?

What is displayed after the following code? list ← [10, 20, 30] APPEND(list, 40) REMOVE(list, 2) DISPLAY(list)

A robot is in a grid and needs to reach a goal. The robot can move forward, turn left, and turn right. Which of the following is NOT a valid approach to solve this problem?

What does the following procedure compute? PROCEDURE mystery(n) { count ← 0 REPEAT UNTIL (n = 0) { n ← n / 2 (integer division) count ← count + 1 } RETURN count }

A programmer writes two versions of a search algorithm. Version A takes 2n steps, and Version B takes n² steps. For what values of n does Version A perform fewer steps?

What is displayed by the following code? list ← [5, 3, 8, 1, 9, 2] result ← list[1] FOR EACH item IN list { IF (item < result) { result ← item } } DISPLAY(result)

Which of the following is true about the efficiency of algorithms?