Algorithm CS Thinking Example 2

Follow the full solution, then compare it with the other examples linked below.

Example 2

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Here is an algorithm: 1. Set total = 0. 2. For each number in the list [3, 7, 2, 8]: add the number to total. 3. Output total. What does this algorithm compute?

Solution

  1. 1
    Step 1: Trace through: total starts at 0. After 3: total = 3. After 7: total = 10. After 2: total = 12. After 8: total = 20.
  2. 2
    Step 2: The algorithm outputs 20.
  3. 3
    Step 3: This algorithm computes the sum of all numbers in the list.

Answer

The algorithm computes the sum of the list. Output: 20.
Tracing through an algorithm step by step helps us understand what it does. This is a fundamental skill in computational thinking and debugging.

About Algorithm

A step-by-step set of instructions for solving a problem or accomplishing a specific task. An algorithm must be precise (every step is unambiguous), finite (it terminates after a bounded number of steps), and effective (each step can actually be carried out).

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More Algorithm Examples

Example 1 easy

Write an algorithm (as numbered steps) for making a cup of tea.

Example 3 easy

Write an algorithm to find the largest number in a list of three numbers: A, B, C.

Example 4 easy

A recipe says, 'Add sugar until it tastes right.' Explain why this is a poor algorithm step and rewr

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