Hdu 3723 Card Game (JAVA, Cattleya number)

It is easy to think of the number of Cattleya, but the complexity of high precision is quite disgusting.

And then he killed it in Java seconds.

Import Java.math.biginteger;import Java.util.scanner;public class Main {static biginteger[] f=new biginteger[5005];     Static biginteger[] C=new biginteger[10005];          Static BigInteger MOD;     static void Init () {f[0]=biginteger.valueof (1);     for (int i=1;i<=5000;i++) {f[i]=f[i-1].multiply (biginteger.valueof (4*i-2));     F[i]=f[i].divide (biginteger.valueof (i+1));     } String str= "1";     for (int i=0;i<100;i++) str+= "0";     Mod=new BigInteger (str);     } public static void Main (string[] args) {init ();     Scanner cin=new Scanner (system.in);     while (Cin.hasnext ()) {int n=cin.nextint ();     C[0]=biginteger.valueof (1);     for (int i=1;i<=n;i++) {c[i]=c[i-1].multiply (biginteger.valueof (n-i+1));     C[i]=c[i].divide (biginteger.valueof (i));     } BigInteger ans=biginteger.valueof (0);     for (int i=0;i*2<=n;i++) {BigInteger tmp=c[i*2].mod (mod). Multiply (F[i].mod (mod));     Ans=ans.add (TMP);     Ans=ans.mod (MoD); } SYSTEM.OUt.println (ANS); }     }}

　　

Hdu 3723 Card Game (JAVA, Cattleya number)