fork download
copy 
  1. import java.util.*;
  2. import java.lang.*;
  3. import java.math.*;
  4.  
  5. class Main {
  6.  
  7.     public enum Distance {
  8.         METER (new BigDecimal("1.0")), // Base Unit is METER
  9.         KM(new BigDecimal("1E3")),
  10.         CM(new BigDecimal("1E-2"));
  11.  
  12.         private final static MathContext MC = new MathContext(30, RoundingMode.HALF_EVEN);
  13.  
  14.         public static long convert(long value, Distance originalUnit, Distance resultingUnit) {
  15.             return resultingUnit.fromBaseUnit(originalUnit.toBaseUnit(value));
  16.         }
  17.  
  18.         private final BigDecimal conversionRatio;
  19.  
  20.         Distance(BigDecimal conversionRatio) {
  21.             this.conversionRatio = conversionRatio;
  22.         }
  23.  
  24.         private long fromBaseUnit(BigDecimal baseUnit) {
  25.             return baseUnit.divide(conversionRatio, MC).longValue();
  26.         }
  27.  
  28.         // returns BigDecimal to avoid rounding two times
  29.         // and possible division by zero
  30.         private BigDecimal toBaseUnit(long originalUnit) {
  31.             return BigDecimal.valueOf(originalUnit).multiply(conversionRatio);
  32.         }
  33.     } 
  34.  
  35.     public static void main (String[] args) throws java.lang.Exception {
  36.         System.out.println("2450 m in km is " + Distance.convert(2450, Distance.METER, Distance.KM));
  37.         System.out.println("178 m in cm is " + Distance.convert(178, Distance.METER, Distance.CM));
  38.         System.out.println("550 cm in m is " + Distance.convert(550, Distance.CM, Distance.METER));
  39.         System.out.println("1 km in cm is " + Distance.convert(1, Distance.KM, Distance.CM));
  40.     }
  41. }
Success #stdin #stdout 0.06s 380224KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
2450 m in km is 2
178 m in cm is 17800
550 cm in m is 5
1 km in cm is 100000
https://ideone.com/xY4DOo
http://stackoverflow.com/questions/17548187/metric-convertions-algorithm-without-if-else-or-switch-case
language:
Java (12.0.1)
created:
10 years ago
visibility:
secret

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!