The Deaf Rats of Hamelin

The Deaf Rats of Hamelin

Story

The Pied Piper has been enlisted to play his magical tune and coax all the rats out of town.

But some of the rats are deaf and are going the wrong way!

Kata Task

How many deaf rats are there?

Legend

• P = The Pied Piper

• O~ = Rat going left

• ~O = Rat going right

Example

• ex1 ~O~O~O~O P has 0 deaf rats

• ex2 P O~ O~ ~O O~ has 1 deaf rat

• ex3 ~O~O~O~OP~O~OO~ has 2 deaf rats

Series

• The deaf rats of Hamelin (2D)

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Solutions

🧠 C++

int countDeafRats(const std::string &town)
{
    //until we found the PP all the rats that goes to the left is deaf
    //after we dound PP all that foes to the right
    bool found_PP = false;
    int deaf_counter  = 0;
    for(auto iter = town.begin(); iter != town.end(); iter++)
    {
        if(*iter == 'P') found_PP=true;

        //going right
        else if(iter[0]=='~' && iter[1]=='O') ++iter , deaf_counter+=found_PP;
        //going left
        else if(iter[0]=='O' && iter[1]=='~') ++iter , deaf_counter+=!found_PP;
    }

    return deaf_counter;
}