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
Note:
For a given n, a gray code sequence is not uniquely defined.
For example, [0,2,3,1]
is also a valid gray code sequence according to the above definition.
For now, the judge is able to judge based on one instance of gray code sequence. Sorry about that.
class Solution {
public:
vector<int> grayCode(int n) {
unsigned int data=0;
vector<int> list;
for(int i=0;i<(1<<n);i++)
list.push_back(0);
for(int loc=0;loc<n;loc++)
{
int bit=0;
int step=1<<loc;
int index=0;
while(index<(1<<n))
{
list[index]=list[index] | (bit<<loc);
step++;
if(step==(2<<loc))
{
bit=1-bit;
step=0;
}
index++;
}
}
return list;
}
};
public:
vector<int> grayCode(int n) {
unsigned int data=0;
vector<int> list;
for(int i=0;i<(1<<n);i++)
list.push_back(0);
for(int loc=0;loc<n;loc++)
{
int bit=0;
int step=1<<loc;
int index=0;
while(index<(1<<n))
{
list[index]=list[index] | (bit<<loc);
step++;
if(step==(2<<loc))
{
bit=1-bit;
step=0;
}
index++;
}
}
return list;
}
};