-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathGrayCode.java
More file actions
44 lines (35 loc) · 909 Bytes
/
Copy pathGrayCode.java
File metadata and controls
44 lines (35 loc) · 909 Bytes
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
// solved. both small and big cases
import java.util.ArrayList;
/*
* Gray Code
The gray code is a binary numeral system where two successive values differ in only one bit.
Given a non-negative integer n representing the total number of bits in the code, print the sequence of gray code. A gray code sequence must begin with 0.
For example, given n = 2, return [0,1,3,2]. Its gray code sequence is:
00 - 0
01 - 1
11 - 3
10 - 2
*/
public class GrayCode {
public static void main(String[] args){
for(int i : grayCode(1)){
System.out.println(i);
}
}
public static ArrayList<Integer> grayCode(int n){
ArrayList<Integer> a = new ArrayList<Integer>();
if(n==0){
a.add(0);
return a;
}
if (n==1){
a.add(0); a.add(1);
return a;
}
ArrayList<Integer> b = grayCode(n-1);
for(int i = b.size()-1; i >=0; i--){
b.add(b.get(i)+(int)Math.pow(2, n-1));
}
return b;
}
}