-
Notifications
You must be signed in to change notification settings - Fork 0
/
024.py
40 lines (27 loc) · 990 Bytes
/
024.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
"""
Project Euler Problem 24
========================
A permutation is an ordered arrangement of objects. For example, 3124 is
one possible permutation of the digits 1, 2, 3 and 4. If all of the
permutations are listed numerically or alphabetically, we call it
lexicographic order. The lexicographic permutations of 0, 1 and 2 are:
012 021 102 120 201 210
What is the millionth lexicographic permutation of the digits 0, 1, 2, 3,
4, 5, 6, 7, 8 and 9?
"""
import euler_utils as utils
digits = [chr(i+48) for i in range(0,10)]
count = 0
permutation = []
for position in range(9,0,-1):
#we could have just divided here, it will straightaway give us the index
factorial = utils.factorial_of(position)
for i in range(len(digits)):
count += factorial
if count >= 1000000:
count -= factorial
permutation.append(digits[i])
digits.remove(digits[i])
break
permutation = permutation + digits
print ''.join(permutation)