Class Name: DigitArith
Method Name: closestToTarget
Parameters: int, int
Returns: int
Implement a class DigitArith, which contains a method closestToTarget. The
method takes 2 ints as parameters: a source and a target. The method performs
3 digit arithmetic operations (defined below) successively on the source and
returns the closest possible result to the target.
Digit Arithmetic Operations:
1. Addition  any digit in the operand can be added to the operand. Defined
when the result is less than 10,000.
2. Subtraction  any digit in the operand can be subtracted from the operand.
Defined when the result is nonnegative.
3. Multiplication  any digit in the operand can be multiplied by the operand.
Defined when the result is less than 10,000.
4. Division  any digit in the operand can divide the operand. The floor of
the result is taken (Integer Division). Defined when the digit is nonzero.
Note:
The operations are performed on the result of the previous operation. ex: for
the second operation, a digit is chosen from the result of the first, not the
source.
No intermediate results can be negative.
The digits are always nonnegative.
The method signature is:
int closestToTarget(int source, int target);
source and target are nonnegative integers less than 1,000.
Example:
If the source is 12 and the target is 85, the three operations that yeild the
result closest to the target are
12, take the (2) digit, and multiply: 12*2=24
24, take the (4), and multply: 24*4=96
96, take the (9), and subtract: 969=87
And the method should return 87.
If the source is 54 and the target is 13,
54/4=13 > 13+1=14 > 141=13.
And the method should return 13.
