HammingDynamicProgramming.h

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#pragma once
 
#include <string/LinearString.h>
 
namespace stringology {
 
namespace simulations {
 
class HammingDynamicProgramming {
public:
    template <class SymbolType>
    static ext::vector<ext::vector<unsigned int>> compute_table(const string::LinearString<SymbolType> & text, const string::LinearString<SymbolType> & pattern, unsigned int errors);
 
    template <class SymbolType>
    static ext::set<unsigned int> search(const string::LinearString<SymbolType> & text, const string::LinearString<SymbolType> & pattern, unsigned int errors);
 
};
 
template <class SymbolType>
ext::vector<ext::vector<unsigned int>> HammingDynamicProgramming::compute_table(const string::LinearString<SymbolType> & text, const string::LinearString<SymbolType> & pattern, unsigned int errors) {
  ext::vector< ext::vector <unsigned int> > table =
    ext::vector<ext::vector<unsigned int> > (
      pattern.getContent().size() + 1,
      ext::vector<unsigned int>(text.getContent().size() + 1, 0)
    );
 
  for(unsigned int j=1; j<=pattern.getContent().size(); j++) {
    table[j][0] = errors + 1;
  }
 
  for(unsigned int i = 1; i<=text.getContent().size(); i++) {
    for(unsigned int j = 1; j<=pattern.getContent().size(); j++) {
      if (pattern.getContent()[j-1] == text.getContent()[i-1]) {
        table[j][i] = table[j-1][i-1];
      } else {
        table[j][i] = table[j-1][i-1] + 1;
      }
    }
  }
 
  return table;
}
 
template <class SymbolType>
ext::set<unsigned int> HammingDynamicProgramming::search(const string::LinearString<SymbolType> & text, const string::LinearString<SymbolType> & pattern, unsigned int errors) {
  auto table = HammingDynamicProgramming::compute_table(text, pattern, errors);
 
  ext::set<unsigned int> result;
 
  for(unsigned int i=1; i<=text.getContent().size(); i++) {
    if (table[pattern.getContent().size()][i] <= errors) {
      result.insert(i);
    }
  }
 
  return result;
}
 
 
 
} // namespace simulations
 
} // namespace stringology