具体思路:
背就完事了;
具体代码:
class Solution {
public:
vector<int> grayCode(int n) {
vector<int>ret = { 0,1 };
for (int i = 2; i <= n; i++) {
int len=ret.size();
for (int j = len-1; j >=0; j--) {
ret.push_back(ret[j] + int(pow(2, i - 1)));
}
}
return ret;
}
};