Another excuse, I had my wisdom tooth extracted, or I could solve them(rev) all.
Hadding a headache, I did not spent so much time on 0CTF, which always has some fun problem to solve.
建議如果看不懂算法的話可以拿起紙筆操作，因為我有點懶不想要畫圖。
感恩彬智讚嘆彬智
建議如果看不懂算法的話可以拿起紙筆操作，因為我有點懶不想要畫圖。
建議如果看不懂算法的話可以拿起紙筆操作，因為我有點懶不想要畫圖。
建議如果看不懂算法的話可以拿起紙筆操作，因為我有點懶不想要畫圖。
SHA-1 is dead - 100 point
SHA-1 is dead
http://sha1.pwn.seccon.jp/
Upload two files satisfy following conditions:
file1 != file2
SHA1(file1) == SHA1(file2)
SHA256(file1) <> SHA256(file2)
2017KiB < sizeof(file1) < 2018KiB
2017KiB < sizeof(file2) < 2018KiB
* 1KiB = 1024 bytes
J...
No I didn’t backup problems…
problem 3
Given an integer (not necessary a decimal number) with n digits, we want to remove $m (\le n)$ digits from this number such that the resulting number is as large as possibe. Design an $O(n)$ time algorithm to solve it.
problem 4
Given a 2-dimensional nn array (or matrix) of 0/1...