delete pics to save space

1.2606.cpp

@@ -0,0 +1,36 @@
+#include<cstdio>
+#include<algorithm>
+using namespace std;
+typedef long long LL;
+const int maxn=1e6+7;
+int n; LL p;
+LL fac[maxn],fac_inv[maxn],inv[maxn];
+LL f[maxn];
+bool is_le[maxn]; int lsize[maxn];
+inline LL C(int n,int m) { return (fac[n]*fac_inv[m]%p)*fac_inv[n-m]%p; }
+LL lucas(int n,int m)
+{
+	if(m>n) return 0;
+	if(m<p&&n<p) return C(n,m);
+	else return lucas(n/p,m/p)*C(n%p,m%p)%p;
+}
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	scanf("%d%lld",&n,&p);
+	fac[0]=1;		for(int i=1;i<=n;i++) fac[i]=fac[i-1]*i%p;
+	inv[1]=1;		for(int i=2;i<=n;i++) inv[i]=(p-p/i)*inv[p%i]%p;
+	fac_inv[0]=1;	for(int i=1;i<=n;i++) fac_inv[i]=fac_inv[i-1]*inv[i]%p;
+	is_le[2]=true;	for(int i=3;i<=n;i++) is_le[i]=is_le[i>>1];
+					for(int i=2;i<=n;i++) lsize[i]=lsize[i-1]+is_le[i];
+	f[0]=f[1]=1;
+	for(int i=2;i<=n;i++)
+	{
+		LL x=lsize[i];
+		f[i]=(lucas(i-1,x)*f[x]%p)*f[i-x-1]%p;
+	}
+	printf("%lld\n",f[n]);
+	return 0;
+}