Problem Description
Conversion between the metric and English measurement systems is relatively simple. Often, it involves either multiplying or dividing by a constant. You must write a program that converts between the following units: 
Input
The first line of input contains a single integer N, (1 ≤ N ≤ 1000) which is the number of datasets that follow.
Each dataset consists of a single line of input containing a floating point (double precision) number, a space and the unit specification for the measurement to be converted. The unit specification is one of kg, lb, l, or g referring to kilograms, pounds, liters and gallons respectively.
Output
For each dataset, you should generate one line of output with the following values: The dataset number as a decimal integer (start counting at one), a space, and the appropriately converted value rounded to 4 decimal places, a space and the unit specification for the converted value.
Sample Input
5
1 kg
2 l
7 lb
3.5 g
0 l
Sample Output
1 2.2046 lb
2 0.5284 g
3 3.1752 kg
4 13.2489 l
5 0.0000 g
题目很简单，就是给出了汇率，让你转换！！！
水题！
import java.util.Scanner;
public class Main{
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
String[] str1 = {"kg","l","lb","g"};
String[] str2 = {"lb","g","kg","l"};
double[] d = {2.2046,0.2642,0.4536,3.7854};
int time = 1;
int t = sc.nextInt();
while(t-->0){
int k=0;
double n = sc.nextDouble();
String s = sc.next();
for(int i=0;i<str1.length;i++){
if(s.equals(str1[i])){
k=i;
n = n*d[i];
break;
}
}
System.out.printf("%d %.4f %s",time,n,str2[k] );
System.out.println();
time++;
}
}
}