qq_45874814的博客

数据结构模板

数论模板 ll fac[maxn], facinv[maxn], inv[maxn]; const ll mod = 1e9 + 7; ll MOD(ll a, ll m) { a %= m; return a >= 0 ? a : a + m; } ll inverse(ll a, ll m) { a = MOD(a, m); if (a <= 1) return a; return MOD((1 - inverse(m, a) * m) / a,