Journal #11

In this chapter I learned about using the search tool with binary logic. Referred as to a “binary search”. This allows for shorter and more efficient ways to gather information for example having a game where a the computer has to figure out the number.

import random
secret_number = random.randrange(1, 129)
guess = 0
while guess != secret_number:
guess = (int)(input("Guess a number 1 to 128: "))
if guess < secret_number:
print("Too low.")
elif guess > secret_number:
print("Too high.")
Using binary search we can reduce the amount of guesses the computer will take. For linear it would guess 1 to 129 but with binary we give the computer an idea of how to do it more efficiently. In this case we will use half of the range of the secret number.
Binary search
key = "Secret Number"
lower_bound = 0
upper_bound = 128
found = False
while lower_bound <= upper_bound and not found:
middle_pos = (lower_bound + upper_bound) // 2
if secret_number[middle_pos] < key:
lower_bound = middle_pos + 1
elif secret_number[middle_pos] > key:
upper_bound = middle_pos - 1
found = True
if found:
print( "The number is ", middle_pos)

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