"Java" "High precision" "combination number" "recursion" poj1737 Connected Graph

http://blog.csdn.net/sdj222555/article/details/12453629

This recursion can be said to be very ingenious.

import java.util.*;import java.io.*;import java.math.*;p ublic class Main{ Static biginteger[] g=new biginteger[60];static biginteger[] f=new biginteger[60];static biginteger[] Pow_2=new    Biginteger[2510];static long[][] c=new long[60][60];p ublic static void Main (string[] argc) {c[0][0]=1l;        for (int i=1;i<=50;++i) {c[i][0]=c[i][i]=1l;        for (int j=1;j<i;++j) {c[i][j]=c[i-1][j]+c[i-1][j-1];    }} Pow_2[0]=biginteger.one;    for (int i=1;i<=2500;++i) {pow_2[i]=pow_2[i-1].multiply (biginteger.valueof (2l)); } g[0]=biginteger.one;for (int i=1;i<=50;++i) {g[i]=biginteger.zero;for (int k=1;k<i;++k) {G[i]=g[i].add (( Biginteger.valueof (C[i-1][k-1])). Multiply (f[k]). Multiply (pow_2[(i-k) * (I-K-1)/2]);} f[i]=pow_2[i* (i-1)/2].subtract (G[i]);} Scanner sc = new Scanner (new Bufferedinputstream (system.in)), while (true) {int n=sc.nextint (), if (n==0) {break;} System.out.println (F[n]);}    Sc.close (); }}

Java, high precision, combined number "recursion" poj1737 Connected Graph