push

ex02/Main.cpp

@@ -4,9 +4,7 @@ int main(int ac, char **av)
 {
 	PmergeMe pm;
 	try {
-		pm.parseInput(ac, av);
-		pm.printVector();
-		pm.printDeque();
+		pm.run(ac, av);
 	} catch (const std::exception &e) {
 		std::cerr << e.what() << std::endl;
 		return 1;

ex02/PmergeMe.cpp

@@ -42,7 +42,8 @@ void PmergeMe::parseInput(int ac, char **av)
 
 	for (int i = 1; i < ac; i++) {
 		std::istringstream ss(av[i]);
-		while (ss >> token) {
+		while (ss >> token)
+		{
 			std::istringstream iss(token);
 			if (!(iss >> n) || !iss.eof() || n < 0)
 				throw std::runtime_error("Error");
@@ -55,3 +56,239 @@ void PmergeMe::parseInput(int ac, char **av)
 	if (_vec.empty())
 		throw std::runtime_error("Error");
 }
+
+void PmergeMe::run(int ac, char **av)
+{
+	std::cout << std::fixed << std::setprecision(5);
+	parseInput(ac, av);
+	std::cout << "Before: ";
+	printVector();
+	sortVector();
+	sortDeque();
+	std::cout << "After:  ";
+	printVector();
+	std::cout << "Time to process a range of " << _vec.size() << " elements with std::vector : " << _vecTime << " us" << std::endl;
+  	std::cout << "Time to process a range of " << _deq.size() << " elements with std::deque  : " << _deqTime << " us" << std::endl;
+}
+
+void PmergeMe::sortVector()
+{
+	clock_t start = clock();
+	_vec = fordJohnsonVec(_vec);
+	clock_t end = clock();
+	_vecTime = (double)(end - start) * 1e6 / CLOCKS_PER_SEC;
+}
+
+std::vector<std::pair<int, int> > makePairs(std::vector<int> v)
+{
+    std::vector<std::pair<int, int> > pairs;
+	for (size_t i = 0; i + 1 < v.size(); i += 2)
+	{
+        int a = v[i];
+        int b = v[i + 1];
+        if (a >= b)
+            pairs.push_back(std::make_pair(a, b));
+        else
+            pairs.push_back(std::make_pair(b, a));
+    }
+    return pairs;
+}
+
+std::vector<std::pair<int, int> > reorderPairs(std::vector<std::pair<int, int> > pairs, std::vector<int> winners)
+{
+    std::vector<std::pair<int, int> > reordered;
+	for (size_t i = 0; i < winners.size(); i++)
+	{
+		for (size_t j = 0; j < pairs.size(); j++)
+		{
+			if (pairs[j].first == winners[i])
+			{
+				reordered.push_back(pairs[j]);
+				break;
+			}
+		}
+	}
+    return reordered;
+}
+
+std::vector<size_t> generateInsertionOrder(std::vector<int> pend)
+{
+    std::vector<size_t> order;
+    std::vector<size_t> jacob;
+	jacob.push_back(0);
+	jacob.push_back(1);
+	while (jacob.back() <= pend.size())
+		jacob.push_back(jacob.back() + 2 * jacob[jacob.size() - 2]);
+	for (size_t k = 3; k < jacob.size(); k++)
+	{
+		size_t high = jacob[k] - 2;
+		if (high >= pend.size()) 
+			high = pend.size() - 1; 
+		size_t low = jacob[k - 1] - 1;
+		for (size_t idx = high + 1; idx > low; idx--)
+			order.push_back(idx - 1);
+    }
+	return order;
+}
+
+std::vector<int> PmergeMe::fordJohnsonVec(std::vector<int> v)
+{
+	if (v.size() <= 1)
+		return v;
+    
+	std::vector<std::pair<int, int> > pairs = makePairs(v);
+	int straggler = 0;
+    bool hasStraggler = false;
+    if (v.size() % 2 != 0)
+    {
+        straggler = v.back();
+        hasStraggler = true;
+    }
+
+	std::vector<int> winners;
+	for (size_t i = 0; i < pairs.size(); i++)
+		winners.push_back(pairs[i].first);
+	winners = fordJohnsonVec(winners);
+	pairs = reorderPairs(pairs, winners);
+
+	std::vector<int> mainChain;
+	mainChain.push_back(pairs[0].second);
+	for (size_t i = 0; i < pairs.size(); i++)
+	{
+		mainChain.push_back(pairs[i].first);
+	}
+
+	std::vector<int> pend;
+	for (size_t i = 1; i < pairs.size(); i++)
+    {
+		pend.push_back(pairs[i].second);
+	}
+
+    std::vector<size_t> order = generateInsertionOrder(pend);
+	for (size_t i = 0; i < order.size(); i++)
+	{
+		int value = pend[order[i]];
+		int aiValue = pairs[order[i] + 1].first;
+		std::vector<int>::iterator aiPos = std::find(mainChain.begin(), mainChain.end(), aiValue);
+		std::vector<int>::iterator insertPos = std::upper_bound(mainChain.begin(), aiPos, value);
+		mainChain.insert(insertPos, value);
+	}
+
+	if (hasStraggler)
+	{
+		std::vector<int>::iterator insertPos = std::upper_bound(mainChain.begin(), mainChain.end(), straggler);
+		mainChain.insert(insertPos, straggler);
+	}
+	return mainChain;
+}
+
+void PmergeMe::sortDeque()
+{
+	clock_t start = clock();
+	_deq = fordJohnsonDeque(_deq);
+	clock_t end = clock();
+	_deqTime = (double)(end - start) * 1e6 / CLOCKS_PER_SEC;
+}
+
+std::deque<std::pair<int, int> > makePairs(std::deque<int> d)
+{
+    std::deque<std::pair<int, int> > pairs;
+	for (size_t i = 0; i + 1 < d.size(); i += 2)
+	{
+        int a = d[i];
+        int b = d[i + 1];
+        if (a >= b)
+            pairs.push_back(std::make_pair(a, b));
+        else
+            pairs.push_back(std::make_pair(b, a));
+    }
+    return pairs;
+}
+
+std::deque<std::pair<int, int> > reorderPairs(std::deque<std::pair<int, int> > pairs, std::deque<int> winners)
+{
+    std::deque<std::pair<int, int> > reordered;
+	for (size_t i = 0; i < winners.size(); i++)
+	{
+		for (size_t j = 0; j < pairs.size(); j++)
+		{
+			if (pairs[j].first == winners[i])
+			{
+				reordered.push_back(pairs[j]);
+				break;
+			}
+		}
+	}
+    return reordered;
+}
+
+std::deque<size_t> generateInsertionOrder(std::deque<int> pend)
+{
+    std::deque<size_t> order;
+    std::deque<size_t> jacob;
+	jacob.push_back(0);
+	jacob.push_back(1);
+	while (jacob.back() <= pend.size())
+		jacob.push_back(jacob.back() + 2 * jacob[jacob.size() - 2]);
+	for (size_t k = 3; k < jacob.size(); k++)
+	{
+		size_t high = jacob[k] - 2;
+		if (high >= pend.size()) 
+			high = pend.size() - 1; 
+		size_t low = jacob[k - 1] - 1;
+		for (size_t idx = high + 1; idx > low; idx--)
+			order.push_back(idx - 1);
+    }
+	return order;
+}
+
+std::deque<int> PmergeMe::fordJohnsonDeque(std::deque<int> d)
+{
+	if (d.size() <= 1)
+		return d;
+    
+	std::deque<std::pair<int, int> > pairs = makePairs(d);
+	int straggler = 0;
+    bool hasStraggler = false;
+    if (d.size() % 2 != 0)
+    {
+        straggler = d.back();
+        hasStraggler = true;
+    }
+
+	std::deque<int> winners;
+	for (size_t i = 0; i < pairs.size(); i++)
+		winners.push_back(pairs[i].first);
+	winners = fordJohnsonDeque(winners);
+	pairs = reorderPairs(pairs, winners);
+
+	std::deque<int> mainChain;
+	mainChain.push_back(pairs[0].second);
+	for (size_t i = 0; i < pairs.size(); i++)
+	{
+		mainChain.push_back(pairs[i].first);
+	}
+
+	std::deque<int> pend;
+	for (size_t i = 1; i < pairs.size(); i++)
+    {
+		pend.push_back(pairs[i].second);
+	}
+
+    std::deque<size_t> order = generateInsertionOrder(pend);
+	for (size_t i = 0; i < order.size(); i++)
+	{
+		int value = pend[order[i]];
+		int aiValue = pairs[order[i] + 1].first;
+		std::deque<int>::iterator aiPos = std::find(mainChain.begin(), mainChain.end(), aiValue);
+		std::deque<int>::iterator insertPos = std::upper_bound(mainChain.begin(), aiPos, value);
+		mainChain.insert(insertPos, value);
+	}
+
+	if (hasStraggler)
+	{
+		std::deque<int>::iterator insertPos = std::upper_bound(mainChain.begin(), mainChain.end(), straggler);
+		mainChain.insert(insertPos, straggler);
+	}
+	return mainChain;
+}

ex02/PmergeMe.hpp

@@ -8,6 +8,7 @@
 #include <sstream>
 #include <stdexcept>
 #include <string>
+#include <iomanip>
 #include <vector>
 
 class PmergeMe
@@ -23,6 +24,8 @@ class PmergeMe
     private:
         std::vector<int> _vec;
         std::deque<int>  _deq;
+        double _vecTime;
+        double _deqTime;
 
 		void printDeque() const;
 		void printVector() const;
@@ -32,6 +35,8 @@ class PmergeMe
         void sortVector();
         void sortDeque();
 
+        std::vector<int> fordJohnsonVec(std::vector<int> v);
+        std::deque<int> fordJohnsonDeque(std::deque<int> v);
 
 };