[Solved] Hw11 Java Programming

1. Some of the number systems used frequently include binary, octal, decimal and hexadecimal systems. Some sample numbers:

base 10 base 2 base 8 base 16

0 0 0 0

1 1 1 1

2 10 2 2

7 111 7 7

8 1000 10 8

9 1001 11 9

10 1010 12 A

11 1011 13 B

15 1111 17 F

16 10000 20 10

Look up web sites like http://www.tutorialspoint.com/computer_fundamentals/computer_number_system.htm

for more information about these systems.

Write and implement the following Java methods:

bToD(String b) //convert binary string b to an equivalent decimal string.

bToO(String b) //convert binary string b to an equivalent octal string.

bToH(String b) //convert binary string b to an equivalent hexadecimal string.

dToB(String d) //convert decimal string d to an equivalent binary string.

oToB(String o) //convert octal string o to an equivalent binary string.

hToB(String h) //convert hexadecimal string h to an equivalent binary string.

convert(int baseFrom, int baseTo, String n) // method to convert n given in baseFrom system to an equivalent number in baseTo system calling two of the above methods needed for conversion. If baseFrom = 10 and baseTo = 16, for example, method convert() will call dToB() followed by bToH() . You may assume that variables baseFrom and baseTo hold 2,8,10, or 16 only, and string n holds a number written in baseFrom system.

* Call the following methods(done in Hw9) from bToD(String b) and dToB(String d) methods appropriately:

String multiply2(String n) { //return 2*n

String r = ;

int c = 0;

for (int i = n.length()-1; i >= 0; i) {

int p = (n.charAt(i)-0)*2+c;

c = p/10;

r = p%10+r;

}

if (c > 0)

r = c+r;

return r;

}

String divide2(String n) { //return n/2

String r = ;

int b = 0;

int i = 0;

if (n.charAt(0) < 2) {

b = 1;

i = 1;

}

for (; i < n.length(); i++) {

int p = (n.charAt(i)-0)+b*10;

b = p%2;

r += p/2;

}

if (r.length() == 0)

r = 0;

return r;

}

The other four methods can be directly implemented manipulating input strings as illustrated in this example:

10110001101011₂ = 26153₈ = 2C6B₁₆

* Note that input and output numbers can be very long and converting them to int or long type before base conversion will cause an overflow error.

* No built-in class or method is allowed to use in this project except:

.next(), .nextLine(), .nextInt(), .nextLong(), .nextDouble(), .nextFloat() in Scanner class;

.length(), .charAt(), .indexOf(), .substring(), .comparedTo(), .equals() in String class;

.max(), .min(), .pow(), .sqrt(), .round(), .floor(), .ceil() in Math class.

.parseInt(), .toString() in Integer class.

* Your main method should use an appropriate loop or menu to test the above methods repeatedly.