blob: 04eccc0243b1c5d23f291b79f83d3a7af043c724 (
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
60
61
62
63
64
65
|
#!/usr/bin/env python3
import json
import sys
def validate_matrix(matrix):
# Calculate the size of the matrix
rows = len(matrix)
cols = len(matrix[0])
for r in range(1, rows):
# Check that all columns are of equal length
if len(matrix[r]) != cols:
raise ValueError(f'Row {r} has different number of columns')
def echelon(matrix: list) -> int:
# Check that the matrix is valid
validate_matrix(matrix)
# Get the position of the first one in each row
leading_one = [None if 1 not in row else row.index(1) for row in matrix]
for row_num in range(len(matrix)):
row = matrix[row_num]
leading_one_pos = leading_one[row_num]
# If the row is all zeros, there is nothing to check
if all(value == 0 for value in row):
continue
# Check the first non zero number is one
for value in row:
if value == 1:
break
if value != 0:
return 0
# Check if the leading one is further right
if row_num != 0:
if leading_one[row_num - 1] is None:
# The previous row was all zeros.
return 0
if leading_one[row_num - 1] > leading_one_pos:
# The previous first one was further to the right
return 0
# Count the number of non-zero values in the column that is the
# leading one. It should be one (this row)
if sum(1 for row in matrix if row[leading_one_pos] != 0) != 1:
return 0
return 1
def main():
# Convert input into a list of list of integers
matrix = json.loads(sys.argv[1])
result = echelon(matrix)
print(result)
if __name__ == '__main__':
main()
|
