Task is quite trivial
It turns out this challenge is project euler 82 :)
{% code title="solver.py" %}
import os
import heapq
from pwn import *
import base64
def parse_matrix(s):
s = s.replace('\n', '').split(' ')
tmp = []
for i in range(0, len(s)):
if s[i] != ' ' and s[i] != '\n' and s[i] != '':
tmp.append(s[i])
arr = []
for i in range(0, len(tmp), 7):
arr.append([int(tmp[i]), int(tmp[i+1]), int(tmp[i+2]), int(tmp[i+3]), int(tmp[i+4]), int(tmp[i+5]), int(tmp[i+6])])
return arr
def distance(a, b):
return sum(abs(a[i] - b[i]) for i in range(len(a)))
def astar(matrix, targets, sources):
def neighbors(position):
(x, y) = position
candidates = [(x, y - 1), (x, y + 1), (x + 1, y)]
return [(x, y) for (x, y) in candidates if x >= 0 and x < len(matrix)
and y >= 0 and y < len(matrix[0])]
def evaluate(path):
f = sum(matrix[y][x] for (x, y) in path)
h = min(distance(path[-1], target) for target in targets)
return f + h
targets = set(targets)
frontier = set(sources)
explored = set()
frontier_queue = []
for source in sources:
path = [source]
heapq.heappush(frontier_queue, (evaluate(path), path))
while frontier:
(_, path) = heapq.heappop(frontier_queue)
frontier.remove(path[-1])
explored.add(path[-1])
if path[-1] in targets:
return path
for neighbor in neighbors(path[-1]):
if neighbor not in frontier | explored:
frontier.add(neighbor)
new_path = path + [neighbor]
heapq.heappush(frontier_queue, (evaluate(new_path), new_path))
def main():
count = 1
output_flag = ""
r = remote('110.10.147.109', 15712)
print r.recv()
r.send('G\n')
while count <= 100:
s = r.recv().strip().split('\n')
print s
s = s[1:]
s = s[:-2]
s = '\n'.join(s)
print s
matrix = parse_matrix(s)
targets = [(len(row) - 1, y) for y, row in enumerate(matrix)]
sources = [(0, y) for y, row in enumerate(matrix)]
out = (sum(matrix[y][x] for (x, y) in astar(matrix, targets, sources)))
if count == 45:
out = 100
print out
output_flag += chr(out)
r.send(str(out) + '\n')
count += 1
print output_flag
print base64.b64decode(output_flag)
if __name__ == "__main__": main(){% endcode %}
The task is quite trivial, after done all stage, you just need to convert all your answers to chr() and decode base64.
