From f0c491da6b98d1981519965cf518f9ea452642dc Mon Sep 17 00:00:00 2001
From: Tomas Capek <tomas@capek.io>
Date: Tue, 1 May 2018 16:51:28 +0200
Subject: [PATCH] Implement simulation for aproximate string matching using
dynamic programming and Levenshtein distance.
---
.../LevenshteinDynamicProgramming.h | 8 ++++---
.../LevenshteinDynamicProgrammingTest.cpp | 24 ++++++-------------
2 files changed, 12 insertions(+), 20 deletions(-)
diff --git a/alib2algo/src/stringology/simulations/LevenshteinDynamicProgramming.h b/alib2algo/src/stringology/simulations/LevenshteinDynamicProgramming.h
index 3c02137536..54a881e4c1 100644
--- a/alib2algo/src/stringology/simulations/LevenshteinDynamicProgramming.h
+++ b/alib2algo/src/stringology/simulations/LevenshteinDynamicProgramming.h
@@ -9,6 +9,7 @@
#define _LEVENSHTEIN_DYNAMIC_PROGRAMMING_H__
#include <algorithm>
+#include <limits.h>
#include <string/LinearString.h>
@@ -46,13 +47,14 @@ ext::vector<ext::vector<unsigned int>> LevenshteinDynamicProgramming::compute_ta
value_a = table[j-1][i-1] + 1;
}
- unsigned int value_b;
+ unsigned int value_b = UINT_MAX;
if(j < pattern.getContent().size()) {
value_b = table[j][i-1] + 1;
- } else {
- value_b = table[j-1][i] + 1;
}
+ value_b = std::min(table[j-1][i] + 1, value_b);
+
+
table[j][i] = std::min({value_a, value_b});
}
}
diff --git a/alib2algo/test-src/stringology/simulations/LevenshteinDynamicProgrammingTest.cpp b/alib2algo/test-src/stringology/simulations/LevenshteinDynamicProgrammingTest.cpp
index 804fa8f365..a87f8f14cc 100644
--- a/alib2algo/test-src/stringology/simulations/LevenshteinDynamicProgrammingTest.cpp
+++ b/alib2algo/test-src/stringology/simulations/LevenshteinDynamicProgrammingTest.cpp
@@ -11,23 +11,13 @@ void LevenshteinDynamicProgrammingTest::testTableConstruction() {
auto pattern = string::LinearString<>("adbbca");
ext::vector<ext::vector<unsigned int>> expected_result = {
- ext::vector<unsigned int>({0, 1, 2, 3, 4, 5, 6}),
- ext::vector<unsigned int>({0, 0, 1, 2, 3, 4, 5}),
- ext::vector<unsigned int>({0, 1, 0, 1, 2, 3, 4}),
- ext::vector<unsigned int>({0, 1, 1, 1, 2, 2, 3}),
- ext::vector<unsigned int>({0, 0, 1, 2, 2, 3, 2}),
- ext::vector<unsigned int>({0, 1, 1, 1, 2, 3, 4}),
- ext::vector<unsigned int>({0, 1, 2, 2, 2, 2, 3}),
- ext::vector<unsigned int>({0, 0, 1, 2, 3, 3, 2}),
- ext::vector<unsigned int>({0, 0, 1, 2, 3, 4, 3}),
- ext::vector<unsigned int>({0, 1, 1, 1, 2, 3, 4}),
- ext::vector<unsigned int>({0, 0, 1, 2, 2, 3, 3}),
- ext::vector<unsigned int>({0, 1, 0, 1, 2, 3, 4}),
- ext::vector<unsigned int>({0, 1, 1, 0, 1, 2, 3}),
- ext::vector<unsigned int>({0, 1, 2, 1, 0, 1, 2}),
- ext::vector<unsigned int>({0, 1, 2, 2, 1, 0, 1}),
- ext::vector<unsigned int>({0, 0, 1, 2, 2, 1, 0}),
-
+ ext::vector<unsigned int>({0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}),
+ ext::vector<unsigned int>({1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 1, 1, 0}),
+ ext::vector<unsigned int>({2, 1, 0, 1, 1, 1, 2, 1, 1, 1, 1, 0, 1, 2, 2, 1}),
+ ext::vector<unsigned int>({3, 2, 1, 1, 2, 1, 2, 2, 2, 1, 2, 1, 0, 1, 2, 2}),
+ ext::vector<unsigned int>({4, 3, 2, 2, 2, 2, 2, 3, 3, 2, 2, 2, 1, 0, 1, 2}),
+ ext::vector<unsigned int>({5, 4, 3, 2, 3, 3, 2, 3, 4, 3, 3, 3, 2, 1, 0, 1}),
+ ext::vector<unsigned int>({6, 5, 4, 3, 2, 4, 3, 2, 3, 4, 3, 4, 3, 2, 1, 0}),
};
CPPUNIT_ASSERT(expected_result == stringology::simulations::LevenshteinDynamicProgramming::compute_table(text, pattern));
--
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