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Home » Problems (hard) » Some More Homework

Some More Homework

Problem code: MARCHA6

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All submissions for this problem are available.

The following problem appeared in the CodeChef March '09 Challenge.

In the computer science class at the school in Byteland, the teacher handed out the following assignment as homework:

"For an integer n, let bn denote the bit parity of the binary representation of n, i.e. bn=0 if n has an even number of ones when written down in the binary system, and bn=1 otherwise. The numbers bn, for n >=0, form an infinite sequence of bits (zeros and ones). Given a sequence c=(c0, ..., cp-1) of p bits, find the first occurrence of sequence c as a subsequence of b (i.e., the smallest value of index k such that for all i between 0 and p-1, we have ci = bi+k)."

And the teacher gave his students several short sequences c, asking them to provide the answers next day. Most, as expected, wrote programs to solve the task. Only Johnny computed the results by hand, claiming (quite correctly) that it was quicker that way. The teacher, slightly exasperated, decided to teach Johnny a lesson, and prepared a harder assignment, just for him.

"Given a sequence c=(c0, ..., cp-1) of p bits, for each s between 0 and p-1, compute the first occurrence of the prefix (c0, ..., cs) of sequence c as a subsequence of b."

And to be doubly sure that Johnny does his homework using a computer, the teacher gave him some really long sequences to deal with. Now, Johnny is in a bit of a spot, because he has never bothered to learn to program. Please help him out!

Input

The first line of input contains a positive integer t < 10, describing the number of tests. Exactly t test cases follow.

Each test case is given in two lines. The first line contains integer p (1<=p<=106, the length of sequence k). The next line contains exactly p space-separated numbers (0 or 1), denoting successive elements of sequence c.

Output

For each test case, print a line containing exactly p space-separated numbers, corresponding to the indexes of the first occurrence of successive prefixes of c as subsequences of b. All indexes are numbered starting from zero. If there is no such occurrence, output -1.

Example

Input:
1
9
1 0 0 1 0 1 1 1 0

Output:
1 2 4 4 8 8 8 -1 -1

Explanation:
The first 16 elements of b are: 0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0
The prefix '1' first appears in b at index 1,
The prefix '1 0' first appears in b at index 2,
The prefixes '1 0 0' and '1 0 0 1' first appear in b at index 4,
... and so on.
There are no occurences of '1 0 0 1 0 1 1 1' in sequence b.


Date:2009-03-18
Time limit:2s-7s
Source limit:50000B
Languages:All except: TCL ERL


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HELP

Program should read from standard input and write to standard output.

After you submit a solution you can see your results by clicking on the [My Submissions] tab on the problem page. Below are the possible results:

  • Accepted Your program ran successfully and gave a correct answer. If there is a score for the problem, this will be displayed in parenthesis next to the checkmark.
  • Time Limit Exceeded Your program was compiled successfully, but it didn't stop before time limit. Try optimizing your approach.
  • Wrong Answer Your program compiled and ran succesfully but the output did not match the expected output.
  • Runtime Error Your code compiled and ran but encountered an error. The most common reasons are using too much memory or dividing by zero. For the specific error codes see the help section.
  • Compilation Error Your code was unable to compile. When you see this icon, click on it for more information.

If you are still having problems, see a sample solution here.

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