codewars055: Buying a car

Instructions

Buying a car

Solution:

//https://www.codewars.com/kata/554a44516729e4d80b000012/train/java
import java.math.BigDecimal;
public class BuyCar{
    public static int[] nbMonths(int startPriceOld, int startPriceNew, int savingperMonth, double percentLossByMonth){
        if(startPriceOld >= startPriceNew){
            return new int[]{0, startPriceOld - startPriceNew};
        }    
        int months = 0;
        int left = 0;
        BigDecimal startPriceOld2 = new BigDecimal(String.valueOf(startPriceOld));
        BigDecimal startPriceNew2 = new BigDecimal(String.valueOf(startPriceNew));
        while(true){
            months++;
            if(months > 1 && months % 2 == 1){
                percentLossByMonth += 0.5;                
            }    
            BigDecimal percent = new BigDecimal(String.valueOf(100.0 - percentLossByMonth) / 100);
            startPriceOld2 = startPriceOld2.multiply(percent);
            startPriceNew2 = startPriceNew2.multiply(percent);
            BigDecimal savings = new BigDecimal(String.valueOf(savingperMonth * months));
            BigDeciaml balance = startPriceOld2.add(savings).substract(startPriceNew2);
            if(balance.compareTo(BigDecimal.ZERO) >= 0){
                left = balance.intValue();
                break;
            }    
        }    
        return new int[]{months, left};
    }    
}

Example Test:

TBD