python math problems

Author: AimenYaseen

python_for_coding_interviews/4_math.py

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+import math
+
+# Division is decimal by default
+print('5 / 2 = ', 5 / 2)
+# output => 2.5
+
+# Double slash rounds down to integer
+print('5 // 2 = ', 5 // 2)
+# output => 2
+
+# CAREFUL: most languages round towards 0 by default
+# python rounds towards minimum value
+# So negative numbers will round down
+print('-3 // 2 = ', -3 // 2)
+# output => -2 but it should be -1
+
+# A workaround for rounding towards zero
+# is to use decimal division and then convert to int.
+print('-3 // 2 = ', int(-3 / 2))
+# output => -1
+
+# Modding is similar to most languages
+print('10 % 3 = ', 10 % 3)
+# output => 1
+
+# Except for negative values
+print('-10 % 3 = ', -10 % 3)
+
+# To be consistent with other languages modulo use math fmod
+
+print(math.fmod(-10, 3))
+
+# More math helpers
+print(math.floor(3 / 2))  # rounds down
+print(math.ceil(3 / 2))  # rounds up
+print(math.sqrt(2))
+print(math.pow(2, 3))
+
+# Max / Min Int
+float("inf")
+float("-inf")
+
+# Python numbers are infinite so they never overflow
+print(math.pow(2, 200))
+
+# But still less than infinity
+print(math.pow(2, 200) < float("inf"))
+# output => True