Damm algorithm: Difference between revisions
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=={{header|C++}}== |
=={{header|C++}}== |
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===Version 1=== |
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{{trans|C#|C sharp}} |
{{trans|C#|C sharp}} |
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<syntaxhighlight lang="cpp">#include <string> |
<syntaxhighlight lang="cpp">#include <string> |
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112946 is valid |
112946 is valid |
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112949 is invalid</pre> |
112949 is invalid</pre> |
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===Version 2=== |
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<syntaxhighlight lang="cpp"> |
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// Compile with: |
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// g++ -std=c++20 -Wall -Wextra -pedantic damm.cpp -o damm |
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#include <iostream> |
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#include <array> // for std::array |
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#include <string> // for std::string, std::to_string and std::string::find |
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const std::array<std::array<int, 10>, 10> table = {{ // Operation table |
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{0, 3, 1, 7, 5, 9, 8, 6, 4, 2}, |
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{7, 0, 9, 2, 1, 5, 4, 8, 6, 3}, |
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{4, 2, 0, 6, 8, 7, 1, 3, 5, 9}, |
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{1, 7, 5, 0, 9, 8, 3, 4, 2, 6}, |
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{6, 1, 2, 3, 0, 4, 5, 9, 7, 8}, |
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{3, 6, 7, 4, 2, 0, 9, 5, 8, 1}, |
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{5, 8, 6, 9, 7, 2, 0, 1, 3, 4}, |
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{8, 9, 4, 5, 3, 6, 2, 0, 1, 7}, |
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{9, 4, 3, 8, 6, 1, 7, 2, 0, 5}, |
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{2, 5, 8, 1, 4, 3, 6, 7, 9, 0} |
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}}; |
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bool damm(int input) { |
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int interim = 0; // initialise to 0 |
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const std::string digit = "0123456789"; |
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for (const auto c : std::to_string(input)) |
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interim = table[interim][digit.find(c)]; |
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// Process the number digit by digit: |
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// 1. The column index = number's digit |
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// 2. The row index = interim digit |
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// 3. Replace interim digit with table entry (table[<interim digit>][<number's digit>]) |
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return interim == 0; // Is interim digit equals zero? If so, the input is valid, invalid otherwise. |
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} |
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int main() { |
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for (const auto num : {5724, 5727, 112946, 112949}) |
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std::cout << num << "\t" << "Checksum is " << (damm(num) ? "valid" : "invalid") << std::endl; |
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return 0; |
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} |
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</syntaxhighlight> |
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{{out}} |
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<pre> |
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5724 Checksum is valid |
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5727 Checksum is invalid |
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112946 Checksum is valid |
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112949 Checksum is invalid |
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</pre> |
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=={{header|Caché ObjectScript}}== |
=={{header|Caché ObjectScript}}== |