Java 大数

import java.math.BigInteger;
import java.util.Scanner;

public class Main {
public static void main(String[] arge){
Scanner cin=new Scanner(System.in);
int t=cin.nextInt();
for(int i=1;i<=t;i++){
BigInteger a=cin.nextBigInteger();
BigInteger b=cin.nextBigInteger();
BigInteger sum=a.add(b);
System.out.println("Case "+i+":");
System.out.println(a+" + "+b+" = "+sum);
if(i!=t) System.out.println();
}
}
}

import java.math.BigDecimal;
import java.util.Scanner;

public class Main{
public static void main(String[]arge){
Scanner cin=new Scanner(System.in);
while(cin.hasNext()){
BigDecimal b=cin.nextBigDecimal();
int n=cin.nextInt();
BigDecimal tar=b.pow(n);
//System.out.println(tar);
String str=tar.toPlainString();//toString会使用科学计数法
int st=0;
while(str.charAt(st)=='0') st++;
int ed=str.length()-1;
while(str.charAt(ed)=='0') ed--;
if(str.charAt(ed)=='.') ed--;//这里小心
for(int i=st;i<=ed;i++){
System.out.print(str.charAt(i));
}
System.out.println();
}
}
}

import java.math.BigInteger;
import java.util.Scanner;
public class Main{
public static void main(String[] arge){
Scanner cin=new Scanner(System.in);
int n;
BigInteger tar;
while(cin.hasNext()){
n=cin.nextInt();
tar=BigInteger.valueOf(1);
for(int i=2;i<=n;i++){
tar=tar.multiply(BigInteger.valueOf(i));
}
System.out.println(tar);
}
}
}