FiniteAutomatonMatcher.cpp

Author: lxylxy123456

FiniteAutomatonMatcher.cpp

@@ -0,0 +1,85 @@
+//  
+//  algorithm - some algorithms in "Introduction to Algorithms", third edition
+//  Copyright (C) 2018  lxylxy123456
+//  
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU Affero General Public License as
+//  published by the Free Software Foundation, either version 3 of the
+//  License, or (at your option) any later version.
+//  
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU Affero General Public License for more details.
+//  
+//  You should have received a copy of the GNU Affero General Public License
+//  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//  
+
+#ifndef MAIN
+#define MAIN
+#define MAIN_FiniteAutomatonMatcher
+#endif
+
+#ifndef FUNC_FiniteAutomatonMatcher
+#define FUNC_FiniteAutomatonMatcher
+
+#include "utils.h"
+
+#include "NaiveStringMatcher.cpp"
+
+template <typename T>
+void FiniteAutomatonMatcher(const std::vector<T>& S, 
+							const std::vector<std::vector<size_t>>& delta, 
+							T o, std::vector<size_t>& ans) {
+	size_t n = S.size(), m = delta.size() - 1; 
+	size_t q = 0; 
+	for (size_t i = 0; i < n; i++) {
+		q = delta[q][S[i] - o]; 
+		if (q == m)
+			ans.push_back(i - m + 1); 
+	}
+}
+
+template <typename T>
+void ComputeTransitionFunction(const std::vector<T>& P, size_t d, T o, 
+								std::vector<std::vector<size_t>>& delta) {
+	size_t m = P.size(); 
+	for (size_t q = 0; q <= m; q++) {
+		delta.push_back(std::vector<size_t>()); 
+		for (size_t a = 0; a <= d; a++) {
+			size_t k = std::min(m, q + 1); 
+			while (k && (P[k-1] - o != (T) a || !equal(P, 0, P, q - k+1, k-1)))
+				k--; 
+			delta[q].push_back(k); 
+		}
+	}
+}
+#endif
+
+#ifdef MAIN_FiniteAutomatonMatcher
+int main(int argc, char *argv[]) {
+	const size_t n = get_argv(argc, argv, 1, 40); 
+	const size_t m = get_argv(argc, argv, 2, 3); 
+	const size_t d = get_argv(argc, argv, 3, 2); 
+	const size_t compute = get_argv(argc, argv, 4, 1); 
+	std::vector<char> S, P; 
+	random_integers<char>(S, 'a', 'a' + d, n); 
+	random_integers<char>(P, 'a', 'a' + d, m); 
+	output_integers(S, ""); 
+	output_integers(P, ""); 
+	std::vector<std::vector<size_t>> delta; 
+	ComputeTransitionFunction(P, d, 'a', delta); 
+	std::vector<size_t> ans; 
+	FiniteAutomatonMatcher(S, delta, 'a', ans); 
+	output_integers(ans); 
+	if (compute) {
+		std::vector<size_t> ans1; 
+		NaiveStringMatcher(S, P, ans1); 
+		output_integers(ans1); 
+		std::cout << std::boolalpha << (ans == ans1) << std::endl; 
+	}
+	return 0; 
+}
+#endif
+

README.md

@@ -207,6 +207,8 @@
 | 31 | PollardRho.cpp				| Pollard Rho							|  977 |
 | 32 | NaiveStringMatcher.cpp		| Naive String Matcher					|  988 |
 | 32 | RabinKarpMatcher.cpp			| Rabin Karp Matcher					|  993 |
+| 32 | FiniteAutomatonMatcher.cpp	| Finite Automaton Matcher				|  999 |
+| 32 | FiniteAutomatonMatcher.cpp	| Compute Transition Function			| 1001 |
 
 # Supplementary Files
 * `utils.h`: Utils