摘要：
Problem G Font: Times New Roman | Verdana | Georgia Font Size: ← → Problem Description S number is the number which the sum of every digit is a prime 阅读全文
摘要：
http://codeforces.com/contest/691/problem/D D. Swaps in Permutation D. Swaps in Permutation You are given a permutation of the numbers 1, 2, ..., n an 阅读全文