Algorithm properties

Learn finiteness, definiteness, input, output and effectiveness.

Finiteness and definiteness

Finiteness means the algorithm stops after a fixed number of steps. A procedure with an infinite loop is not an algorithm.

Definiteness means each step has a single interpretation. 'Stir a bit' is ambiguous; 'stir for 5 seconds' is definite.

Input is the values given at the start; zero or more. Output is the result produced; at least one is required.

Effectiveness means each step is simple and doable. 'Find the infinite number' is not effective because it cannot be done in finite time.

Write square(n). Return n * n and print 36 with print(square(6)).

Show example solution

def square(n):
    # Square a number
    return n * n
print(square(6))

Effectiveness

Each step must be doable in ____ time.

Show answer

Each step must be doable in finite time.

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