2020牛客多校第六场

B.Binary Vectorc++ 看样例，求逆元异或前缀和spa #include<bits/stdc++.h> using namespace std; typedef unsigned long long ll; const int mod=1e9+7; const int maxn=2e7+10; ll ksm(ll x) { ll ans=1,n=mod-2; whil

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