zoj2988--------------Conversions

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:
Type
Metric
English
equivalent
Weight
1.000
kilograms
2.2046 pounds
Weight
0.4536
kilograms
1.0000 pound
Volume
1.0000
liter
0.2642 gallons
Volume
3.7854
liters
1.0000 gallon
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
소수점 뒷자리와 출력 형식을 유지하면
코드:

#include <iostream>
#include <string>
#include <cstdio>
using namespace std;

int main()
{
	int n;
	cin>>n;
	for(int i=1;i<=n;i++)
	{
		double x;
		string s;
		cin>>x>>s;
		if(s=="kg")
		{
			cout<<i;
			printf(" %.4lf lb
",x*2.2046);}
		else if(s=="lb")
		{
			cout<<i;
			printf(" %.4lf kg
",x*0.4536);}
		else if(s=="l")
		{
			cout<<i;
			printf(" %.4lf g
",x*0.2642);}
		else if(s=="g")
		{
			cout<<i;	
			printf(" %.4lf l
",x*3.7854);}
	}
	return 0;	
}