add solutions pract03

1 files changed, 106 insertions, 0 deletions

diff --git a/Practicum/pract03/solutions.cpp b/Practicum/pract03/solutions.cpp
new file mode 100644
index 0000000..2370a93
--- /dev/null
+++ b/Practicum/pract03/solutions.cpp
@@ -0,0 +1,106 @@
+#include <iostream>
+#include <algorithm>
+#include <vector>
+using namespace std;
+
+//Task 1
+void orderByFirstLetter(vector<string>& words)
+{
+	auto first = words.begin();
+	auto last = words.end();
+
+	for (char letter = 'a'; letter <= 'z'; letter++)
+	{
+		auto new_beg = partition(first, last, [letter](const string& str) { return str[0] == letter; });
+		first = new_beg;
+	}
+}
+
+//Task 2
+bool isEven(int n)
+{
+	return n % 2 == 0;
+}
+
+bool isOdd(int n)
+{
+	return n % 2;
+}
+
+template <class Pred>
+void mergeSortedPred(vector<int>& res, const vector<int>& first, const vector<int>& second, Pred p)
+{
+	auto beg1 = first.begin();
+	auto beg2 = second.begin();
+
+	auto end1 = first.end();
+	auto end2 = second.end();
+
+	while (beg1 != end1 && beg2 != end2)
+	{
+		if (p(*beg1) && p(*beg2))
+		{
+			if (*beg1 <= *beg2)
+			{
+				res.push_back(*beg1);
+				++beg1;
+			}
+			else
+			{
+				res.push_back(*beg2);
+				++beg2;
+			}
+		} 
+		else
+		{
+			if (!p(*beg1))
+				++beg1;
+
+			if (!p(*beg2))
+				++beg2;
+		}
+	}
+
+	while (beg1 != end1)
+	{
+		if (p(*beg1))
+			res.push_back(*beg1);
+
+		++beg1;
+	}
+
+	while (beg2 != end2)
+	{
+		if (p(*beg2))
+			res.push_back(*beg2);
+
+		++beg2;
+	}
+}
+vector<int> mergeSortedEvensAndOdds(const vector<int>& first, const vector<int>& second)
+{
+	vector<int> res;
+	mergeSortedPred(res, first, second, isEven);
+	mergeSortedPred(res, first, second, isOdd);
+
+	return res;
+}
+
+int main()
+{
+	//task 1
+	vector<string> v = { "banana", "apple", "alpaca", "cat", "biscuit", "elephant", "string", "house", "progress", "trousers", "mouse" };
+	orderByFirstLetter(v);
+
+	for (auto it = v.begin(); it != v.end(); ++it)
+		cout << *it << " ";
+
+	//task 2
+	vector<int> v1 = { 1, 2, 3, 4, 5 };
+	vector<int> v2 = { 5, 17, 32, 80, 81, 82, 83 };
+
+	vector<int> res = mergeSortedEvensAndOdds(v1, v2);
+
+	for (auto it = res.begin(); it != res.end(); ++it)
+		std::cout << *it << " ";
+}