Mock CCC '20 Contest 1 J4 - A Binary Problem

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Points: 5 (partial)
Time limit: 1.0s
Memory limit: 1G

Problem type
Allowed languages
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koosaga lives on a street with N houses, all equally spaced apart. Each house either has the lights on or off. koosaga rates a house with a score equal to the minimum distance, in house units, that he must travel to be at a house that has its lights on.

koosaga wants to compute the sum of the ratings of all the houses on his street.


1 \le N \le 10^6

In tests worth 5 marks, N \le 10^3.

At least one house will always have its lights on.

Input Specification

The first line contains a single positive integer, N.

The next line contains a binary string. If the ith character of the string is 1, then the ith house has its lights on. Otherwise, the ith character of the string is 0 and that house has its lights off.

Output Specification

Output the sum of all the ratings.

Sample Input 1


Sample Output 1


Explanation for Sample 1

Every house is illuminated, so every house has a rating of 0.

Sample Input 2


Sample Output 2


Explanation for Sample 2

The first and last house have ratings of 0, and the second and third house each have a rating of 1.


  • 0
    ItzMidnightShadowWolf  commented on Aug. 14, 2020, 10:20 a.m. edited

    Can someone tell me what to do..?



    • 1
      boolean  commented on Aug. 14, 2020, 11:10 a.m.

      As for all problems, read the problem carefully and try and construct a solution. If you're stuck, there's an editorial explaining this question that you can access right above "Points:5 (partial)".

      For future reference, it usually isn't wise to ask for help on a question in the comments without trying to code it first. Asking for help with specific parts of the problem or parts of your code is fine, but don't ask the comments how to do an entire question. If you need to ask someone this type of question, the DMOJ slack is a better place to do it. Hope this helps!