Fib.cpp

Author: lxylxy123456

Fib.cpp

@@ -0,0 +1,73 @@
+//  
+//  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_Fib
+#endif
+
+#ifndef FUNC_Fib
+#define FUNC_Fib
+
+#include <thread>
+#include "utils.h"
+
+size_t Fib(size_t n) {
+	if (n <= 1)
+		return n; 
+	else {
+		size_t x = Fib(n - 1); 
+		size_t y = Fib(n - 2); 
+		return x + y; 
+	}
+}
+
+void PFib(size_t n, size_t* ret) {
+	if (n <= 1)
+		*ret = n; 
+	else {
+		size_t x, y; 
+		std::thread t1(PFib, n - 1, &x); 
+		PFib(n - 2, &y); 
+		t1.join(); 
+		*ret = x + y; 
+	}
+}
+
+size_t PFib(size_t n) {
+	size_t ret; 
+	PFib(n, &ret); 
+	return ret; 
+}
+#endif
+
+#ifdef MAIN_Fib
+int main(int argc, char *argv[]) {
+	std::cout << "n\ta\tb\ta == b" << std::endl; 
+	for (int i = 1; i < std::max(argc, 2); i++) {
+		size_t n = get_argv(argc, argv, i, 10); 
+		size_t a = Fib(n); 
+		std::cout << n << '\t' << a << '\t' << std::flush; 
+		size_t b = PFib(n); 
+		std::cout << b << '\t'; 
+		std::cout << std::boolalpha << (a == b) << std::endl; 
+	}
+	return 0; 
+}
+#endif
+

Makefile

@@ -16,7 +16,7 @@
 #  along with this program.  If not, see <https:#www.gnu.org/licenses/>.
 #  
 
-CXXFLAGS=-Wall -g -std=c++11
+CXXFLAGS=-Wall -g -std=c++11 -pthread
 
 SOURCES = $(wildcard *.cpp)
 

README.md

@@ -171,6 +171,8 @@
 | 26 | RelabelToFront.cpp			| Initialize Preflow					|  740 |
 | 26 | RelabelToFront.cpp			| Discharge								|  751 |
 | 26 | RelabelToFront.cpp			| Relabel To Front						|  755 |
+| 27 | Fib.cpp						| Fib									|  775 |
+| 27 | Fib.cpp						| P Fib									|  776 |
 
 # Supplementary Files
 * `utils.h`: Utils