mirror of https://gitee.com/bigwinds/arangodb
62 lines
2.0 KiB
C++
62 lines
2.0 KiB
C++
////////////////////////////////////////////////////////////////////////////////
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/// DISCLAIMER
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///
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/// Copyright 2014-2016 ArangoDB GmbH, Cologne, Germany
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/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
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///
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/// Licensed under the Apache License, Version 2.0 (the "License");
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/// you may not use this file except in compliance with the License.
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/// You may obtain a copy of the License at
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///
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/// http://www.apache.org/licenses/LICENSE-2.0
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///
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/// Unless required by applicable law or agreed to in writing, software
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/// distributed under the License is distributed on an "AS IS" BASIS,
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/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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/// See the License for the specific language governing permissions and
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/// limitations under the License.
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///
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/// Copyright holder is ArangoDB GmbH, Cologne, Germany
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///
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/// @author Jan Steemann
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////////////////////////////////////////////////////////////////////////////////
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#include "levenshtein.h"
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#include <numeric>
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////////////////////////////////////////////////////////////////////////////////
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/// @brief calculate the levenshtein distance of the two strings
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////////////////////////////////////////////////////////////////////////////////
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int TRI_Levenshtein(std::string const& lhs, std::string const& rhs) {
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int const lhsLength = static_cast<int>(lhs.size());
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int const rhsLength = static_cast<int>(rhs.size());
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int* col = new int[lhsLength + 1];
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int start = 1;
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// fill with initial values
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std::iota(col + start, col + lhsLength + 1, start);
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for (int x = start; x <= rhsLength; ++x) {
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col[0] = x;
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int last = x - start;
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for (int y = start; y <= lhsLength; ++y) {
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int const save = col[y];
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col[y] = (std::min)({
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col[y] + 1, // deletion
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col[y - 1] + 1, // insertion
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last + (lhs[y - 1] == rhs[x - 1] ? 0 : 1) // substitution
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});
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last = save;
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}
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}
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// fetch final value
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int result = col[lhsLength];
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// free memory
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delete[] col;
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return result;
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}
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