HDU高精度总结（java大数类）

  HDU1002   A + B Problem II

【题意】大数相加

【链接】http://acm.hdu.edu.cn/showproblem.php?pid=1002

Sample Input

2
1 2
112233445566778899 998877665544332211

 

Sample Output

Case 1:
1 + 2 = 3

Case 2:
112233445566778899 + 998877665544332211 = 1111111111111111110

代码：

import java.io.*;
import java.util.*;
import java.math.BigInteger;//声明BigInteger大数类
import java.lang.*;
public class Main
{
    public static void main(String args[])
    {
        Scanner cin = new Scanner(System.in);
        int t,i=1;
        t = cin.nextInt();
        int tot = 0;
        BigInteger a,b,c; //BigInteger类型
        while (i<=t)
        {
            a=cin.nextBigInteger();
            b=cin.nextBigInteger();
            c=a.add(b);
            System.out.println("Case "+i+":");
            System.out.println(a+" + "+b+" = "+c);
            if(i<t) System.out.println("");
            i++;
        }
    }
}

HDU1042 N!

【题意】大数阶乘

【链接】

pid=1042" style="color:rgb(202,0,0); text-decoration:none">http://acm.hdu.edu.cn/showproblem.php?pid=1042

Sample Input

1
2
3

 

Sample Output

1
2
6

代码：

import java.io.*;
import java.util.*;
import java.math.BigInteger;//声明BigInteger大数类
import java.lang.*;
public class FF
{
    public static void main(String args[])
    {
        Scanner cin = new Scanner(System.in);
        while(cin.hasNext())
        {
         int n=cin.nextInt();
         BigInteger ans=BigInteger.ONE;
         for(int i=1; i<=n; ++i)
         {
        	ans=ans.multiply(BigInteger.valueOf(i));
         }
         System.out.println(ans);
         System.gc();	//调用垃圾回收机制
        }
    }
}

HDU 1047 Integer Inquiry

【题意】多个大数相加

【链接】http://acm.hdu.edu.cn/showproblem.php?pid=1047

Sample Input

1

123456789012345678901234567890
123456789012345678901234567890
123456789012345678901234567890
0

 

Sample Output

370370367037037036703703703670

注意下格式

代码:

import java.io.*;
import java.util.*;
import java.math.BigInteger;//声明BigInteger大数类
import java.lang.*;
public class Main
{
    public static void main(String args[])
    {
        Scanner cin = new Scanner(System.in);
        int n=cin.nextInt();
        while(n-->0)
        {
         BigInteger a,b,c;
         b=BigInteger.ZERO;
         while(cin.hasNextBigInteger())
         {
        	 c=BigInteger.ZERO;
        	 c=cin.nextBigInteger();
        	 if(!c.equals(BigInteger.valueOf(0)))
        		 b=b.add(c);
        	 else
        	 {
        		 System.out.println(b);
        		 if(n!=0)
        			 System.out.println("");
        		 break;
        	 }
         }
         System.gc();
        }
    }
}

HDU 1715  大菲波数

【题意】RT

【链接】http://acm.hdu.edu.cn/showproblem.php?pid=1715

Sample Input

5
1
2
3
4
5

 

Sample Output

1
1
2
3
5

代码：

import java.io.*;
import java.util.*;
import java.math.BigInteger;//声明BigInteger大数类
import java.lang.*;
public class Main
{
    public static void main(String args[])
    {
        Scanner cin = new Scanner(System.in);
        int n=cin.nextInt();
         BigInteger fac[]= new BigInteger[1001];
        fac[0]=BigInteger.ZERO;//初始赋值
        fac[1]=BigInteger.ONE;
        for(int i=2; i<=1000; ++i) fac[i]=fac[i-1].add(fac[i-2]);
        while(n-->0)
        {
        	int a;
        	a=cin.nextInt();
        	System.out.println(fac[a]);
        }
         //System.gc();
    }
}

HDU 1063  Exponentiation

【题意】高精度幂

【链接】http://acm.hdu.edu.cn/showproblem.php?pid=1063

Sample Input

95.123 12
0.4321 20
5.1234 15
6.7592  9
98.999 10
1.0100 12

 

Sample Output

548815620517731830194541.899025343415715973535967221869852721
.00000005148554641076956121994511276767154838481760200726351203835429763013462401
43992025569.928573701266488041146654993318703707511666295476720493953024
29448126.764121021618164430206909037173276672
90429072743629540498.107596019456651774561044010001
1.126825030131969720661201

最简形式是去掉后面的 0，以及小于 1 的小数的小数点前的 0

实现高精度幂java方法：

（1）调用pow函数

（2）for循环

代码：

import java.io.*;
import java.util.*;
import java.math.BigDecimal;
import java.math.BigInteger;//声明BigInteger大数类
import java.lang.*;
public class Main
{
    public static void main(String args[])
    {
        Scanner cin = new Scanner(System.in);
        while(cin.hasNext())
        {
        BigDecimal ans=cin.nextBigDecimal();
        int n=cin.nextInt();
        String res=ans.pow(n).stripTrailingZeros().toPlainString();//整数去掉小数点和后面的0

       if(res.startsWith("0"))//去掉前导0
           {
        	   res=res.substring(1);
           }
           System.out.println(res);
      /*  BigDecimal a=BigDecimal.ONE;
        int n=cin.nextInt();
        for(int i=1; i<=n; ++i)
        	a=a.multiply(ans);
        String res=a.stripTrailingZeros().toPlainString();
           if(res.startsWith("0"))
           {
        	   res=res.substring(1);
           }
           System.out.println(res);
       */
        }
    }
}

HDU 1316   How Many Fibs?

【题意】区间fibonacci

【链接】http://acm.hdu.edu.cn/showproblem.php?pid=1316

Sample Input

10 100
1234567890 9876543210
0 0

 

Sample Output

5
4

代码：

import java.io.*;
import java.util.*;
import java.math.BigDecimal;
import java.math.BigInteger;//声明BigInteger大数类
public class Main
{
    public static void main(String args[])
    {
        Scanner cin = new Scanner(System.in);
        BigInteger a,b;
        int ans,i;
        BigInteger fac[]=new BigInteger[1005];
        BigInteger zero=BigInteger.ZERO;
        fac[1]=BigInteger.valueOf(1);
        fac[2]=BigInteger.valueOf(2);
        for(i=3; i<1005; ++i) fac[i]=fac[i-1].add(fac[i-2]);
        while(cin.hasNextBigInteger())
        {
           a=cin.nextBigInteger();
           b=cin.nextBigInteger();
           if(a.compareTo(zero)==0&&b.compareTo(zero)==0) break;
           for(ans=0,i=1; i<1005; ++i)
           {
        	   if(a.compareTo(fac[i])<=0&&b.compareTo(fac[i])>=0) ans++;
        	   if(b.compareTo(fac[i])<0) break;
           }
          System.out.println(ans);
        }
    }
}

HDU 1753   大明A+B (高精度)

【题意】高精度小数相加

【链接】http://acm.hdu.edu.cn/showproblem.php?

pid=1753

Sample Input

1.1 2.9
1.1111111111 2.3444323343
1 1.1

 

Sample Output

4
3.4555434454
2.1

代码：

import java.io.*;
import java.util.*;
import java.math.BigDecimal;
import java.math.BigInteger;//声明BigInteger大数类
public class Main
{
    public static void main(String args[])
    {
        Scanner cin = new Scanner(System.in);
        BigDecimal a,b,c;
        while(cin.hasNextBigDecimal())
        {
        	a=cin.nextBigDecimal();
        	b=cin.nextBigDecimal();
        	c=a.add(b);
        	String res=c.stripTrailingZeros().toPlainString();
        	System.out.println(res);
        }
    }
}