blob: db2c65edd5abb7ae2012a8efa435a3123d5e287a (
plain)
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
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
|
#!/usr/bin/env python3
# Challenge 107
#
# TASK #1 - Self-descriptive Numbers
# Submitted by: Mohammad S Anwar
# Write a script to display the first three self-descriptive numbers. As per
# wikipedia, the definition of Self-descriptive Number is
#
# In mathematics, a self-descriptive number is an integer m that in a given
# base b is b digits long in which each digit d at position n (the most
# significant digit being at position 0 and the least significant at position
# b-1) counts how many instances of digit n are in m.
#
# For example:
#
# 1210 is a four-digit self-descriptive number:
#
# position 0 has value 1 i.e. there is only one 0 in the number
# position 1 has value 2 i.e. there are two 1 in the number
# position 2 has value 1 i.e. there is only one 2 in the number
# position 3 has value 0 i.e. there is no 3 in the number
# Output
# 1210, 2020, 21200
def is_self_descriptive(n):
for i in range(len(n)):
count = len(list(filter(lambda x: x==i, n)))
if n[i]!=count:
return False
return True
def increment(n, base):
i = len(n)-1
while i >= 0:
n[i] += 1
if n[i] < base:
return
else:
n[i] = 0
i -= 1
n.insert(0, 1)
def self_descriptive(num):
found = []
base = 4
while True:
n = [0]*base
n[0] = 1
while len(n)==base:
if is_self_descriptive(n):
found.append("".join([str(x) for x in n]))
if len(found) >= num:
return found
increment(n, base)
base += 1
self_descr = self_descriptive(3)
print(", ".join(self_descr))
|
