The 2021 ICPC Asia Shanghai Regional Programming Contest - B. Strange Permutations 题解
: [inclusion-exclusion, combinatorics, math, FFT, team training, merge] ...
: [inclusion-exclusion, combinatorics, math, FFT, team training, merge] ...
题意 Zayin进行了 \(n\) 场比赛, 获胜 \(m\) 局,其中最长连胜是 \(k\) ,问有多少种情况 思路 问题转化 考虑败场分割胜场(这是一个经典解法:隔板法),问题转化为 ...