diff --git a/.gitignore b/.gitignore
index 510c73d..8b16403 100644
--- a/.gitignore
+++ b/.gitignore
@@ -102,6 +102,8 @@ venv.bak/
 # Rope project settings
 .ropeproject
 
+.idea
+
 # mkdocs documentation
 /site
 
diff --git a/README.md b/README.md
index 84b53db..8dfb2c0 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,12 @@
-# Algorithms
- 
+# Algorithms lab_4
+
+## Task
+Build directed and weighted graph from input and implement Dijkstra algorithm to find average distance from vertex S 
+to all available vertexes
+
+## How to run
+  + `cd` into folder where you want to store this repository
+  + Clone this repository `git clone https://github.com/MKruchok/Algorithms.git`
+  + Choose branch lab_4 with command `git checkout lab_4`
+  + Go into folder with files with command `cd Algorithms`
+  + run `py main.py` on Windows 
\ No newline at end of file
diff --git a/dijkstra.out b/dijkstra.out
new file mode 100644
index 0000000..d00518b
--- /dev/null
+++ b/dijkstra.out
@@ -0,0 +1 @@
+5.555555555555555
\ No newline at end of file
diff --git a/main.py b/main.py
new file mode 100644
index 0000000..f473c8a
--- /dev/null
+++ b/main.py
@@ -0,0 +1,31 @@
+from queue import PriorityQueue
+from collections import defaultdict
+
+
+class Graph:
+
+    def __init__(self, vertices):
+        self.vertices = vertices
+        self.graph = defaultdict(list)
+        self.distance = [999] * self.vertices
+
+    def add_line(self, first_vert, second_vert, weight):
+        self.graph[first_vert].append((second_vert, weight))
+        self.graph[second_vert].append((first_vert, weight))
+
+    def dijkstra(self, main_vertex):
+        self.distance[main_vertex] = 0
+        q = PriorityQueue()
+        q.put((self.distance[main_vertex], main_vertex))
+        while not q.empty():
+            dist, current_vertex = q.get()
+            for adj_vertex, weight in self.graph[current_vertex]:
+                if self.distance[current_vertex] + weight < self.distance[adj_vertex]:
+                    self.distance[adj_vertex] = self.distance[current_vertex] + weight
+                    q.put((self.distance[adj_vertex], adj_vertex))
+        return self.distance
+
+
+def insert_out(result):
+    file = open("dijkstra.out", 'w')
+    file.write(str(result))
diff --git a/test.py b/test.py
new file mode 100644
index 0000000..bb16f3b
--- /dev/null
+++ b/test.py
@@ -0,0 +1,65 @@
+import unittest
+from main import Graph
+
+
+class TestDijkstra(unittest.TestCase):
+    def setUp(self):
+        self.graph = Graph(9)
+        self.graph.add_line(2, 3, 6)
+        self.graph.add_line(1, 6, 12)
+        self.graph.add_line(1, 7, 24)
+        self.graph.add_line(1, 2, 9)
+        self.graph.add_line(0, 4, 1)
+        self.graph.add_line(0, 1, 14)
+        self.graph.add_line(4, 8, 5)
+        self.graph.add_line(3, 5, 5)
+        self.graph.add_line(2, 4, 34)
+        self.graph.add_line(3, 4, 3)
+        self.graph.add_line(4, 5, 9)
+        self.graph.add_line(4, 7, 1)
+        self.graph.add_line(5, 8, 12)
+        self.graph.add_line(7, 8, 3)
+        self.graph.add_line(6, 7, 1)
+
+    def test_0(self):
+        self.distance_main = self.graph.dijkstra(0)
+        self.distance_sum = 0
+        for end_vertex in range(len(self.distance_main)):
+            print("Distance from", 0, "to", end_vertex, "==", self.distance_main[end_vertex])
+            self.distance_sum += self.distance_main[end_vertex]
+        result = [0, 14, 10, 4, 1, 9, 3, 2, 5]
+        self.middle = self.distance_sum / len(self.distance_main)
+        print("Arithmetic mean ==", round(self.middle, 2))
+        self.assertEqual(self.distance_main, result)
+
+    def test_1(self):
+        result = [14, 0, 9, 15, 14, 20, 12, 13, 16]
+        self.assertEqual(self.graph.dijkstra(1), result)
+
+    def test_2(self):
+        result = [10, 9, 0, 6, 9, 11, 11, 10, 13]
+        self.assertEqual(self.graph.dijkstra(2), result)
+
+    def test_3(self):
+        result = [4, 15, 6, 0, 3, 5, 5, 4, 7]
+        self.assertEqual(self.graph.dijkstra(3), result)
+
+    def test_4(self):
+        result = [1, 14, 9, 3, 0, 8, 2, 1, 4]
+        self.assertEqual(self.graph.dijkstra(4), result)
+
+    def test_5(self):
+        result = [9, 20, 11, 5, 8, 0, 10, 9, 12]
+        self.assertEqual(self.graph.dijkstra(5), result)
+
+    def test_6(self):
+        result = [3, 12, 11, 5, 2, 10, 0, 1, 4]
+        self.assertEqual(self.graph.dijkstra(6), result)
+
+    def test_7(self):
+        result = [2, 13, 10, 4, 1, 9, 1, 0, 3]
+        self.assertEqual(self.graph.dijkstra(7), result)
+
+    def test_8(self):
+        result = [5, 16, 13, 7, 4, 12, 4, 3, 0]
+        self.assertEqual(self.graph.dijkstra(8), result)