leetcode/java/GrayCode.java at master · sureleo/leetcode

20 lines (20 loc) · 641 Bytes

//http://www.cnblogs.com/springfor/p/3889222.html

//compare to code I wrote about two month ago,

//this approach is way easier

//my way is a little bit hacky

public class Solution {

public List<Integer> grayCode(int n) {

if (n == 0) {

List<Integer> result = new ArrayList<Integer>();

result.add(0);

return result;

}

List<Integer> result = new ArrayList<Integer>();

result = grayCode(n-1);

int addNumber = 1 << n-1;

for (int i = result.size()-1; i >= 0; i--) {

result.add(addNumber + result.get(i));

}

return result;

}

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