結果

問題 No.336 門松列列
コンテスト
ユーザー holeguma
提出日時 2016-01-15 23:37:35
言語 Java
(openjdk 23)
結果
TLE  
実行時間 -
コード長 4,049 bytes
コンパイル時間 2,259 ms
コンパイル使用メモリ 78,656 KB
実行使用メモリ 118,600 KB
最終ジャッジ日時 2024-09-19 19:33:35
合計ジャッジ時間 8,694 ms
ジャッジサーバーID
（参考情報） 		judge5 / judge2
このコードへのチャレンジ
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ファイルパターン 結果
sample -- * 4
other TLE * 1 -- * 7
権限があれば一括ダウンロードができます

ソースコード

diff # 

import java.io.InputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.InputMismatchException;
import java.util.NoSuchElementException;
import java.math.BigInteger;

public class Main{

static PrintWriter out;
static InputReader ir;

static void solve(){
 final long MOD=(long)1e9+7;
 int n=ir.nextInt();
 if(n<=2){
  out.println(0);
  return;
 }
 long[] fact=factArray(n,MOD),factInv=factInverseArray(n,MOD);
 long ans=fact[n];
 int sig=-1;
 for(int i=3;i<=n;i++){
  ans+=sig*comb(n,i,fact,factInv,MOD)*fact[n-i]*(n-i+1)*2;
  while(ans<0) ans+=MOD;
  ans%=MOD;
  sig*=-1;
 }
 out.println(ans);
}

public static long mod_inverse(long a,long MOD){
 long[] ret=extgcd(a,MOD);
 return (MOD+ret[0]%MOD)%MOD;
}

public static long[] extgcd(long a,long b){
 long[] ret=new long[3];
 ret[2]=_extgcd(a,b,ret);
 return ret;
}

private static long _extgcd(long a,long b,long[] x){
 long g=a;
 x[0]=1;
 x[1]=0;
 if(b!=0){
  g=_extgcd(b,a%b,x);
  long temp=x[0]; x[0]=x[1]; x[1]=temp;
  x[1]-=(a/b)*x[0];
 }
 return g;
}

private static long[] factArray(int n,long MOD){
 long[] ret=new long[n+1];
 ret[0]=1%MOD;
 for(int i=1;i<=n;i++){
  ret[i]=ret[i-1]*i;
  ret[i]%=MOD;
 }
 return ret;
}

private static long[] factInverseArray(int n,long MOD){
 long[] ret=new long[n+1];
 ret[0]=1;
 for(int i=1;i<=n;i++){
  ret[i]=ret[i-1]*mod_inverse((long)i,MOD)%MOD;
 }
 return ret;
}

public static long comb(int n,int m,long[] fact,long[] factInv,long MOD){
 long ret=fact[n];
 ret*=factInv[m];
 ret%=MOD;
 ret*=factInv[n-m];
 ret%=MOD;
 return ret;
}

public static void main(String[] args) throws Exception{
 ir=new InputReader(System.in);
 out=new PrintWriter(System.out);
 solve();
 out.flush();
}

static class InputReader {
 private InputStream in;
 private byte[] buffer=new byte[1024];
 private int curbuf;
 private int lenbuf;

 public InputReader(InputStream in) {this.in=in; this.curbuf=this.lenbuf=0;}
 
 public boolean hasNextByte() {
  if(curbuf>=lenbuf){
   curbuf= 0;
   try{
    lenbuf=in.read(buffer);
   }catch(IOException e) {
    throw new InputMismatchException();
   }
   if(lenbuf<=0) return false;
  }
  return true;
 }

 private int readByte(){if(hasNextByte()) return buffer[curbuf++]; else return -1;}
 
 private boolean isSpaceChar(int c){return !(c>=33&&c<=126);}
 
 private void skip(){while(hasNextByte()&&isSpaceChar(buffer[curbuf])) curbuf++;}
 
 public boolean hasNext(){skip(); return hasNextByte();}
 
 public String next(){
  if(!hasNext()) throw new NoSuchElementException();
  StringBuilder sb=new StringBuilder();
  int b=readByte();
  while(!isSpaceChar(b)){
   sb.appendCodePoint(b);
   b=readByte();
  }
  return sb.toString();
 }
 
 public int nextInt() {
  if(!hasNext()) throw new NoSuchElementException();
  int c=readByte();
  while (isSpaceChar(c)) c=readByte();
  boolean minus=false;
  if (c=='-') {
   minus=true;
   c=readByte();
  }
  int res=0;
  do{
   if(c<'0'||c>'9') throw new InputMismatchException();
   res=res*10+c-'0';
   c=readByte();
  }while(!isSpaceChar(c));
  return (minus)?-res:res;
 }
 
 public long nextLong() {
  if(!hasNext()) throw new NoSuchElementException();
  int c=readByte();
  while (isSpaceChar(c)) c=readByte();
  boolean minus=false;
  if (c=='-') {
   minus=true;
   c=readByte();
  }
  long res = 0;
  do{
   if(c<'0'||c>'9') throw new InputMismatchException();
   res=res*10+c-'0';
   c=readByte();
  }while(!isSpaceChar(c));
  return (minus)?-res:res;
 }

 public double nextDouble(){return Double.parseDouble(next());}

 public BigInteger nextBigInteger(){return new BigInteger(next());}

 public int[] nextIntArray(int n){
  int[] a=new int[n];
  for(int i=0;i<n;i++) a[i]=nextInt();
  return a;
 }

 public long[] nextLongArray(int n){
  long[] a=new long[n];
  for(int i=0;i<n;i++) a[i]=nextLong();
  return a;
 }

 public char[][] nextCharMap(int n,int m){
  char[][] map=new char[n][m];
  for(int i=0;i<n;i++) map[i]=next().toCharArray();
  return map;
 }
}
}
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