UVa - 389 Basically Speaking

//java solution
import java.util.*;
import java.util.regex.*;
import java.io.*;
import java.awt.geom.*;
import java.math.*;
import java.text.*;

class Main
{


    public static void main (String args[])  // entry point from OS
    {
        Main myWork = new Main();  // create a dynamic instance
        myWork.Begin();            // the true entry point
    }

    void Begin()
    {

String s,cs;
int b,t;
BigInteger a;
Scanner sc=new Scanner(new BufferedReader(new InputStreamReader(System.in)));
PrintWriter pr=new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
try
 {
sc=new Scanner(new BufferedReader(new FileReader("F:\\INPUT.TXT")));
}
 catch(Exception e)
 {
     System.exit(0);
 }

   //default delimiter : "\\s+"
            // that means spaces , tabs , newlines(form feeds , carriage returns)
            // are skipped
            while(sc.hasNext())
    {
    s=sc.next();
    b=sc.nextInt();
    t=sc.nextInt();
    a=new BigInteger(s,b);
    cs=a.toString(t);
        if(cs.length()>7)
            pr.printf("%7s%n","ERROR");
        else
        {
            cs=cs.toUpperCase();
            pr.printf("%7s%n",cs);
        }
        }
    pr.close();
    sc.close();
    }
}

UVa - 355 The Bases Are Loaded

//java solution
import java.util.*;
import java.util.regex.*;
import java.io.*;
import java.awt.geom.*;
import java.math.*;
import java.text.*;

class Main
{


    public static void main (String args[])  // entry point from OS
    {
        Main myWork = new Main();  // create a dynamic instance
        myWork.Begin();            // the true entry point
    }

    void Begin()
    {

String s,cs;
int b,t;
BigInteger a;
Scanner sc=new Scanner(new BufferedReader(new InputStreamReader(System.in)));
PrintWriter pr=new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
try
 {
sc=new Scanner(new BufferedReader(new FileReader("F:\\INPUT.TXT")));
}
 catch(Exception e)
 {
     System.exit(0);
 }

   //default delimiter : "\\s+"
            // that means spaces , tabs , newlines(form feeds , carriage returns)
            // are skipped
            while(sc.hasNext())
    {
   
    b=sc.nextInt();
    t=sc.nextInt();
    s=sc.next();
        try
        {
        a=new BigInteger(s,b);
        cs=a.toString(t).toUpperCase();
        pr.printf("%s base %d = %s base %d%n",s,b,cs,t);
        }
        catch(Exception ex){
        pr.printf("%s is an illegal base %d number%n",s,b);
        }
        }
    pr.close();
    sc.close();
    }
}

UVa - 446 Kibbles `n' Bits `n' Bits `n' Bits

//java solution
import java.util.*;
import java.util.regex.*;
import java.io.*;
import java.awt.*;
import java.awt.geom.*;
import java.math.*;
import java.text.*;

class Main
{
  

    public static void main (String args[])  // entry point from OS
    {
        Main myWork = new Main();  // create a dynamic instance
        myWork.Begin();            // the true entry point
    }

    void Begin()
    {
        String sa,sb,tsa,tsb,so;long l;
        BigInteger a=new BigInteger("0",16),b=new BigInteger("0",16),c=new BigInteger("0",16);
Scanner sc=new Scanner(new BufferedReader(new InputStreamReader(System.in)));
PrintWriter pr=new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));       
try
 {
          sc=new Scanner(new BufferedReader(new FileReader("INPUT.TXT")));
}
 catch(Exception e)
 {
     System.exit(0);
 }
       
       
   //default delimiter : "\\s+"
            // that means spaces , tabs , newlines(form feeds , carriage returns)
            // are skipped
        l=sc.nextLong();
        for(long i=0;i<l;i++)
        {
            sa=sc.next();so=sc.next();sb=sc.next();
            a=new BigInteger(sa,16);b=new BigInteger(sb,16);
        if(so.compareTo("+")==0)
        {
            c=a.add(b);
        }
        else
        {
            c=a.subtract(b);
        }
        tsa=a.toString(2);tsb=b.toString(2);
        tsa=String.format("%13s",tsa);
        tsb=String.format("%13s",tsb);
        tsa=tsa.replace(' ','0');
        tsb=tsb.replace(' ','0');
        pr.printf("%s %s %s = %s%n",tsa,so,tsb,c.toString(10));
        }
    pr.close();
    sc.close();
    }
}

UVa - 343 What Base Is This?

 //java solution to problem 343
import java.util.*;
import java.util.regex.*;
import java.io.*;
import java.awt.geom.*;
import java.math.*;
import java.text.*;

class Main
{


    public static void main (String args[])  // entry point from OS
    {
        Main myWork = new Main();  // create a dynamic instance
        myWork.Begin();            // the true entry point
    }
int findminbase(String s)
{
int i=1,j;
for(char c : s.toCharArray())
{
    if(c>='A') j=c-'A'+10;
    else j=c-'0';
    if(i<j) i=j;
}
i++;
return i;
}
    void Begin()
    {
String sa,sb,tsa,tsb;
BigInteger a=new BigInteger("0"),b=new BigInteger("0");
int i=0,j=0,m1=2,m2=2;
boolean err=false;
Scanner sc=new Scanner(new BufferedReader(new InputStreamReader(System.in)));
PrintWriter pr=new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
try
 {
sc=new Scanner(new BufferedReader(new FileReader("INPUT.TXT")));
}
 catch(Exception e)
 {
     System.exit(0);
 }

   //default delimiter : "\\s+"
            // that means spaces , tabs , newlines(form feeds , carriage returns)
            // are skipped
            while(sc.hasNext())
    {
                err=false;
sa=sc.next();sb=sc.next();
m1=findminbase(sa);m2=findminbase(sb);
mylabel:
for(i=m1;i<=36;i++)
{
    for(j=m2;j<=36;j++)
    {
    try
        {
    a=new BigInteger(sa,i);b=new BigInteger(sb,j);
    }
    catch(Exception ex){continue;}
tsa=a.toString(10);tsb=b.toString(10);

if(tsa.compareTo(tsb)==0) break mylabel;
    }
            }
if(i>36 && j>36) pr.printf("%s is not equal to %s in any base 2..36%n",sa,sb);
else pr.printf("%s (base %d) = %s (base %d)%n",sa,i,sb,j);
      }
    pr.close();
    sc.close();
    }
}