Searching and Sorting

Searching and Sorting/Searching and Sorting.cpp

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+#include <iostream>
+#include <vector>
+
+template <typename T>
+void PrintVector(std::vector<T> v)
+{
+	for (const auto& e : v)
+		std::cout << e << ", ";
+	std::cout << std::endl;
+}
+
+void Swap(int* a, int* b)
+{
+	int temp = *b;
+	*b = *a;
+	*a = temp;
+}
+
+std::vector<int> SelectionSort(std::vector<int> in)
+{
+	for (int i = 0; i < in.size(); i++)
+	{
+		int indexOfSmallest = i;
+		for (int j = i; j < in.size(); j++)
+		{
+			if (in[indexOfSmallest] > in[j])
+			{
+				indexOfSmallest = j;
+			}
+		}
+		if (indexOfSmallest != i)
+		{
+			Swap(&in[i], &in[indexOfSmallest]);
+		}
+	}
+	return in;
+}
+
+std::vector<int> InsersionSort(std::vector<int> in)
+{
+	for (int i = 0; i < in.size(); i++)
+	{
+		int itemToInsert = in[i];
+		int indexHole = i;
+		while (indexHole > 0 && in[indexHole - 1] > itemToInsert)
+		{
+			in[indexHole] = in[indexHole - 1];
+			indexHole--;
+		}
+
+		in[indexHole] = itemToInsert;
+	}
+	return in;
+}
+
+std::vector<int> BubbleSort(std::vector<int> in)
+{
+	for (int i = 0; i < in.size(); i++)
+	{
+		for (int j = 0; j < in.size() - 1; j++)
+		{
+			if (in[j] > in[j + 1])
+			{
+				Swap(&in[j], &in[j + 1]);
+			}
+		}
+	}
+	return in;
+}
+
+int LinearSearch(std::vector<int> vals, int lookup)
+{
+	for (const auto& i : vals)
+	{
+		if (i == lookup)
+		{
+			return lookup;
+		}
+	}
+}
+
+
+std::vector<int> SubsetVector(std::vector<int> in, int start, int end)
+{
+	std::vector<int> result(start - end + 1);
+	std::copy(in.begin() + start, in.begin() + end + 1, result.begin());
+	return result;
+}
+
+int BinarySearch(std::vector<int> set, int lookup)
+{
+	if (set[set.size() / 2] == lookup) return lookup;
+	if (set[set.size() / 2] > lookup) return BinarySearch(SubsetVector(set, set.size() / 2, set.size()), lookup);
+	if (set[set.size() / 2] < lookup) return BinarySearch(SubsetVector(set, 0, set.size() / 2), lookup);
+}
+
+
+int TernarySearch(std::vector<int> set, int lookup)
+{
+	if (set.size() == 1) return set[0];
+	if (set.size() == 2) return BinarySearch(set, lookup);
+
+	int firstThird = 0;
+	int secondThird = set.size() / 3;
+	int thirdThird = (set.size() / 3) * 2;
+	int lastThird = set.size();
+
+	if (set[firstThird] > lookup && set[secondThird] < lookup) return TernarySearch(SubsetVector(set, firstThird, secondThird), lookup);
+	if (set[secondThird] > lookup && set[thirdThird] < lookup) return TernarySearch(SubsetVector(set, secondThird, thirdThird), lookup);
+	if (set[thirdThird] > lookup && set[lastThird] < lookup)   return TernarySearch(SubsetVector(set, thirdThird, lastThird), lookup);
+}
+
+int main()
+{
+	std::vector<int> sorted;
+
+	sorted = SelectionSort({ 1, 4, 3, 5, 7, 4, 3, 7, 8, 2, 10, 5, 100 });
+
+	PrintVector(sorted);
+
+	sorted = InsersionSort({ 1, 4, 3, 5, 7, 4, 3, 7, 8, 2, 10, 5, 100 });
+
+	PrintVector(sorted);
+
+	sorted = BubbleSort({ 1, 4, 3, 5, 7, 4, 3, 7, 8, 2, 10, 5, 100 });
+
+	PrintVector(sorted);
+
+
+	std::cout << std::endl;
+
+
+	int lookup = 0;
+
+	lookup = LinearSearch(BubbleSort({ 1, 4, 3, 5, 7, 4, 3, 7, 8, 2, 10, 5, 100 }), 5);
+	std::cout << lookup << std::endl;
+
+	lookup = BinarySearch(BubbleSort({ 1, 4, 3, 5, 7, 4, 3, 7, 8, 2, 10, 5, 100 }), 5);
+	std::cout << lookup << std::endl;
+
+	lookup = TernarySearch(BubbleSort({ 1, 4, 3, 5, 7, 4, 3, 7, 8, 2, 10, 5, 100 }), 5);
+	std::cout << lookup << std::endl;
+}
+