fork download
copy 
  1. # Integer logarithm.
  2.  
  3. def ilog_floor(x, base):
  4.     if x <= 0:
  5.         raise ValueError('math domain error')
  6.     r = 0
  7.     while True:
  8.         x //= base
  9.         if x == 0:
  10.             return r
  11.         r += 1
  12.  
  13. def ilog_ceil(x, base):
  14.     if x <= 0:
  15.         raise ValueError('math domain error')
  16.     r = 0
  17.     while x != 1:
  18.         x = -(x // -base)
  19.         r += 1
  20.     return r
  21.  
  22. # ..
  23.  
  24. import math
  25.  
  26. basemax = 10
  27. xmax = 1000
  28.  
  29. for base in range(2, basemax+1):
  30.     for x in range(1, xmax+1):
  31.         u = math.floor(math.log(x, base))
  32.         v = ilog_floor(x, base)
  33.         if u != v:
  34.             print('floor/log:', (x, base), 'u:', u, 'v:', v)
  35.             print(f'{base}**{u} = {base**u}')
  36.             print(f'{base}**{v} = {base**v}')
  37.  
  38. for base in range(2, basemax+1):
  39.     for x in range(1, xmax+1):
  40.         u = math.ceil(math.log(x, base))
  41.         v = ilog_ceil(x, base)
  42.         if u != v:
  43.             print('ceil/log:', (x, base), 'u:', u, 'v:', v)
  44.             print(f'{base}**{u} = {base**u}')
  45.             print(f'{base}**{v} = {base**v}')
Success #stdin #stdout 0.14s 14264KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
floor/log: (243, 3) u: 4 v: 5
3**4 = 81
3**5 = 243
floor/log: (1000, 10) u: 2 v: 3
10**2 = 100
10**3 = 1000
ceil/log: (125, 5) u: 4 v: 3
5**4 = 625
5**3 = 125
ceil/log: (216, 6) u: 4 v: 3
6**4 = 1296
6**3 = 216
https://ideone.com/63QsZe
language:
Python 3 (python  3.12)
created:
7 days ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!