Damm algorithm: Difference between revisions
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=={{header|C++}}==
===Version 1===
{{trans|C#|C sharp}}
<syntaxhighlight lang="cpp">#include <string>
Line 798 ⟶ 799:
112946 is valid
112949 is invalid</pre>
===Version 2===
<syntaxhighlight lang="cpp">
// Compile with:
// g++ -std=c++20 -Wall -Wextra -pedantic damm.cpp -o damm
#include <iostream>
#include <array> // for std::array
#include <string> // for std::string, std::to_string and std::string::find
const std::array<std::array<int, 10>, 10> table = {{ // Operation table
{0, 3, 1, 7, 5, 9, 8, 6, 4, 2},
{7, 0, 9, 2, 1, 5, 4, 8, 6, 3},
{4, 2, 0, 6, 8, 7, 1, 3, 5, 9},
{1, 7, 5, 0, 9, 8, 3, 4, 2, 6},
{6, 1, 2, 3, 0, 4, 5, 9, 7, 8},
{3, 6, 7, 4, 2, 0, 9, 5, 8, 1},
{5, 8, 6, 9, 7, 2, 0, 1, 3, 4},
{8, 9, 4, 5, 3, 6, 2, 0, 1, 7},
{9, 4, 3, 8, 6, 1, 7, 2, 0, 5},
{2, 5, 8, 1, 4, 3, 6, 7, 9, 0}
}};
bool damm(int input) {
int interim = 0; // initialise to 0
const std::string digit = "0123456789";
for (const auto c : std::to_string(input))
interim = table[interim][digit.find(c)];
// Process the number digit by digit:
// 1. The column index = number's digit
// 2. The row index = interim digit
// 3. Replace interim digit with table entry (table[<interim digit>][<number's digit>])
return interim == 0; // Is interim digit equals zero? If so, the input is valid, invalid otherwise.
}
int main() {
for (const auto num : {5724, 5727, 112946, 112949})
std::cout << num << "\t" << "Checksum is " << (damm(num) ? "valid" : "invalid") << std::endl;
return 0;
}
</syntaxhighlight>
{{out}}
<pre>
5724 Checksum is valid
5727 Checksum is invalid
112946 Checksum is valid
112949 Checksum is invalid
</pre>
=={{header|Caché ObjectScript}}==
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