From LeetCode, the definition of the "Two Sum Problem" is:
Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target.
You may assume that each input would have exactly one solution, and you may not use the same element twice.
You can return the answer in any order.
Example 1:
nums = [2,7,11,15]
target = 9
Output: [0,1]
The current solution on LeetCode with the fastest runtime on Python is the following:
class Solution(object):
def twoSum(self, nums, target):
from zlib import decompress
from base64 import b64decode
open('user.out', 'wb').write(decompress(b64decode("eJyLNtRRMIjlijbSUTAEUggekqAxiqCJjoIRhgZjFEGESgMMJVDtphDKGK7SGKFy2FKwAAFyTRGilkCgowAkLIAcMx0IaQmSN9IxAqsz0zE0B9IGOsDABQCpFVmV"))),exit(0)
From my perspective, I have no idea how this code would be generated. It seems like they taking an advantage of a vulnerability in the interpreter, but even that isn't clear.
How exactly does this script run and how does it perform the actions noted above in the problem description?
Base64 allows to encode binary data as text, which then is decompressed
from zlib import decompress
from base64 import b64decode
print(decompress(b64decode("eJyLNtRRMIjlijbSUTAEUggekqAxiqCJjoIRhgZjFEGESgMMJVDtphDKGK7SGKFy2FKwAAFyTRGilkCgowAkLIAcMx0IaQmSN9IxAqsz0zE0B9IGOsDABQCpFVmV")))
gives output
b'[1, 0]\n[2, 1]\n[1, 0]\n[2, 0]\n[2, 1]\n[3, 0]\n[2, 0]\n[4, 2]\n[2, 1]\n[1, 0]\n[3, 2]\n[2, 1]\n[2, 0]\n[4, 0]\n[1, 0]\n[3, 2]\n[4, 2]\n[5, 2]\n[3, 0]\n[4, 3]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[1, 0]\n[4, 0]\n[11, 5]\n[1, 0]\n[9999, 9998]\n[6,8]\n[6,9]\n[12,25]\n[16,17]\n[0,1]\n'
so author just stored expected output and is then writing it to user.out which I presume is then tested by judge.