摘要:
s-palindrome s-palindrome Let's call a string "s-palindrome" if it is symmetric about the middle of the string. For example, the string "oHo" is "s-pa 阅读全文
摘要:
Swaps in Permutation Swaps in Permutation You are given a permutation of the numbers 1, 2, ..., n and m pairs of positions (aj, bj). At each step you 阅读全文