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comparison python/example/array_sum.py @ 837:5ba219864529

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add example program
author Jeff Hammel <k0scist@gmail.com>
date Mon, 27 Mar 2017 14:05:29 -0700
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836:0fa456446fea 837:5ba219864529
1 #!/usr/bin/env python
2
3 """
4 given a `value` and an array,
5 if the sum of two numbers in the array
6 total the value, return `True`
7 (exit 0):
8
9 ./array_sum.py 3 1 2 4 # YES! because 1+2=3
10
11 ./array_sum.py 4 1 2 5 6 # NO!
12 """
13
14 import argparse
15 import sys
16
17
18 def sum_of_two(value, *array):
19
20 start = 0
21 end = len(array) - 1
22 complements = []
23 while start < end:
24 start_val = array[start]
25 end_val = array[end]
26 _sum = start_val + end_val
27 if _sum == value:
28 complements.append((start_val, end_val))
29 end -= 1
30 start +=1
31 continue
32 if _sum > value:
33 end -= 1
34 else:
35 start += 1
36 return complements
37
38
39 def main(args=sys.argv[1:]):
40
41 parser = argparse.ArgumentParser(description=__doc__)
42 parser.add_argument('value', type=int)
43 parser.add_argument('array', type=int, nargs='+')
44 options = parser.parse_args(args)
45
46 retval = sum_of_two(options.value, *options.array)
47
48 print (retval)
49
50 sys.exit(0 if retval else 1)
51
52
53 if __name__ == '__main__':
54 main()