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
60
61
62
63
64
65
66
67
68
|
#!/usr/bin/python3
# https://theweeklychallenge.org/blog/perl-weekly-challenge-261/#TASK2
#
# Task 2: Multiply by Two
# =======================
#
# You are given an array of integers, @ints and an integer $start.
#
# Write a script to do the followings:
#
# a) Look for $start in the array @ints, if found multiply the number by 2
# b) If not found stop the process otherwise repeat
#
# In the end return the final value.
#
## Example 1
##
## Input: @ints = (5,3,6,1,12) and $start = 3
## Output: 24
##
## Step 1: 3 is in the array so 3 x 2 = 6
## Step 2: 6 is in the array so 6 x 2 = 12
## Step 3: 12 is in the array so 12 x 2 = 24
##
## 24 is not found in the array so return 24.
#
## Example 2
##
## Input: @ints = (1,2,4,3) and $start = 1
## Output: 8
##
## Step 1: 1 is in the array so 1 x 2 = 2
## Step 2: 2 is in the array so 2 x 2 = 4
## Step 3: 4 is in the array so 4 x 2 = 8
##
## 8 is not found in the array so return 8.
#
## Example 3
##
## Input: @ints = (5,6,7) and $start = 2
## Output: 2
##
## 2 is not found in the array so return 2.
#
############################################################
##
## discussion
##
############################################################
#
# Instead of walking the list for every round, we create a
# hash with the list elements as keys, which makes the lookup
# easier. The we just check in a loop whether the current value
# is still there.
def multiply_by_two(ints: list, start: int) -> None:
print("Input: (", ", ".join(str(x) for x in ints), "), ", start, sep="")
hash: dict = {}
for x in ints:
hash[x] = 1
while start in hash:
start *= 2
print(f"Output: {start}")
multiply_by_two( [5,3,6,1,12], 3);
multiply_by_two( [1,2,4,3], 1);
multiply_by_two( [5,6,7], 2);
|
