Create 5868_zufezzt.cpp

From http://www.cnblogs.com/zufezzt/p/5866141.html

HDOJ/5868_zufezzt.cpp

@@ -0,0 +1,147 @@
+#pragma comment(linker, "/STACK:1024000000,1024000000")
+#include<cstdio>
+#include<cstring>
+#include<cmath>
+#include<algorithm>
+#include<vector>
+#include<map>
+#include<set>
+#include<queue>
+#include<stack>
+#include<iostream>
+using namespace std;
+typedef long long LL;
+const double pi=acos(-1.0),eps=1e-6;
+void File()
+{
+    freopen("D:\\in.txt","r",stdin);
+    freopen("D:\\out.txt","w",stdout);
+}
+template <class T>
+inline void read(T &x)
+{
+    char c=getchar(); x=0;
+    while(!isdigit(c)) c=getchar();
+    while(isdigit(c)) {x=x*10+c-'0'; c=getchar();}
+}
+
+LL n,mod=1e9+7;
+
+LL extend_gcd(LL a,LL b,LL &x,LL &y)
+{
+    if(a==0&&b==0) return -1;
+    if(b==0){x=1;y=0;return a;}
+    LL d=extend_gcd(b,a%b,y,x);
+    y-=a/b*x;
+    return d;
+}
+
+LL mod_reverse(LL a,LL n)
+{
+    LL x,y;
+    LL d=extend_gcd(a,n,x,y);
+    if(d==1) return (x%n+n)%n;
+    else return -1;
+}
+
+LL phi(LL n)
+{
+     LL res=n,a=n;
+     for(int i=2;i*i<=a;i++)
+     {
+         if(a%i==0)
+         {
+             res=res/i*(i-1);
+             while(a%i==0) a/=i;
+         }
+     }
+     if(a>1) res=res/a*(a-1);
+     return res;
+}
+
+struct Matrix
+{
+    LL A[3][3];
+    int R, C;
+    Matrix operator*(Matrix b);
+};
+
+Matrix X, Y, Z;
+
+Matrix Matrix::operator*(Matrix b)
+{
+    Matrix c;
+    memset(c.A, 0, sizeof(c.A));
+    int i, j, k;
+    for (i = 1; i <= R; i++)
+        for (j = 1; j <= b.C; j++)
+            for (k = 1; k <= C; k++)
+                c.A[i][j] = (c.A[i][j] + (A[i][k] * b.A[k][j]) % mod) % mod;
+    c.R = R; c.C = b.C;
+    return c;
+}
+
+void init()
+{
+    memset(X.A, 0, sizeof X.A);
+    memset(Y.A, 0, sizeof Y.A);
+    memset(Z.A, 0, sizeof Z.A);
+
+    Y.R = 2; Y.C = 2;
+    for (int i = 1; i <= 2; i++) Y.A[i][i] = 1;
+
+    X.R = 2; X.C = 2;
+    X.A[1][1]=0; X.A[1][2]=1;
+    X.A[2][1]=1; X.A[2][2]=1;
+
+    Z.R = 1; Z.C = 2;
+    Z.A[1][1]=0; Z.A[1][2]=1;
+}
+
+LL work(int x)
+{
+    x--;
+    while (x)
+    {
+        if (x % 2 == 1) Y = Y*X;
+        x = x >> 1;
+        X = X*X;
+    }
+    Z = Z*Y;
+    return Z.A[1][2];
+}
+
+LL fib(int x)
+{
+    if(x==0) return 0;
+    init();
+    return work(x);
+}
+
+int main()
+{
+    while(~scanf("%lld",&n))
+    {
+        if(n==1) { printf("2\n"); continue; }
+        LL ans=0;
+
+        for(LL i=1;i*i<=n;i++)
+        {
+            if(n%i!=0) continue;
+
+            LL t=phi(n/i)*((fib(i-1)+fib(i+1))%mod)%mod;
+            ans=(ans+t)%mod;
+
+            if(n/i!=i)
+            {
+                t=phi(i)*((fib(n/i-1)+fib(n/i+1))%mod)%mod;
+                ans=(ans+t)%mod;
+            }
+        }
+
+        LL ni=mod_reverse(n,mod);
+        ans=ans*ni%mod;
+        printf("%lld\n",ans);
+    }
+    return 0;
+}