49 lines
1.4 KiB
Python
49 lines
1.4 KiB
Python
#!/usr/bin/env python3
|
|
|
|
# By starting at the top of the triangle below and moving to adjacent numbers on the row below, the maximum total from top to bottom is 23.
|
|
#
|
|
# 3
|
|
# 7 4
|
|
# 2 4 6
|
|
# 8 5 9 3
|
|
#
|
|
# That is, 3 + 7 + 4 + 9 = 23.
|
|
# Find the maximum total from top to bottom in p067_triangle.txt (right click and 'Save Link/Target As...'), a 15K text file containing a triangle
|
|
# with one-hundred rows.
|
|
#
|
|
# NOTE: This is a much more difficult version of Problem 18. It is not possible to try every route to solve this problem, as there are 299 altogether!
|
|
# If you could check one trillion (1012) routes every second it would take over twenty billion years to check them all.
|
|
# There is an efficient algorithm to solve it. ;o)
|
|
|
|
import sys
|
|
|
|
from projecteuler import find_max_path, timing
|
|
|
|
|
|
@timing
|
|
def p067():
|
|
triang = []
|
|
|
|
try:
|
|
with open('p067_triangle.txt', 'r', encoding='utf-8') as fp:
|
|
for line in fp:
|
|
triang.append(line.strip('\n').split())
|
|
except FileNotFoundError:
|
|
print('Error while opening file p067_triangle.txt')
|
|
sys.exit(1)
|
|
|
|
l = len(triang)
|
|
|
|
for i in range(l):
|
|
triang[i] = list(map(int, triang[i]))
|
|
|
|
# Use the function implemented in projecteuler.c to find the maximum path.
|
|
max_ = find_max_path(triang, 100)
|
|
|
|
print('Project Euler, Problem 67')
|
|
print(f'Answer: {max_}')
|
|
|
|
|
|
if __name__ == '__main__':
|
|
p067()
|