pwnable.kr coins 1

main.py

import subprocess
import socket
import sys
N = 0
C = 0
left, right, mid = 0, 0, 0

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect(("0.0.0.0", 9007))

while True:
    lines = s.recv(512).splitlines()
    for line in lines:
        if "expire" in line:
            break
        if not(line.isdigit() or line.startswith("N=")):
            print "|", line
            sys.stdout.flush()
        if line.startswith("N="):
            N = int(line[line.index("=") + 1: line.index(" ")])
            C = int(line[line.rindex("=")+1:])

            left = 0
            right = N
            mid = right/2 + right%2

            payload = " ".join(str(x) for x in range(left, mid)) + "\n"
            s.send(payload)
        if line.isdigit():
            weight = int(line)
            if weight < (mid-left)*10:
                right = mid
            else:
                left = mid
            mid = left + (right-left)/2 + (right-left)%2

            payload = " ".join(str(x) for x in range(left, mid)) + "\n"
            s.send(payload)