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FiniteAutomatonMatcher.cpp
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FiniteAutomatonMatcher.cpp

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

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

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