From 04598d33f64a0d967c88622c0628e33913c5f960 Mon Sep 17 00:00:00 2001
From: v-v-d <v-v-d@bk.ru>
Date: Sun, 25 Aug 2019 22:38:57 +0300
Subject: [PATCH 1/2] task 1 done

---
 Lesson_8/1.py | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 51 insertions(+), 1 deletion(-)

diff --git a/Lesson_8/1.py b/Lesson_8/1.py
index 1c09ac75..9b973674 100644
--- a/Lesson_8/1.py
+++ b/Lesson_8/1.py
@@ -1,3 +1,53 @@
 """
 1. Закодируйте любую строку из трех слов по алгоритму Хаффмана.
-"""
\ No newline at end of file
+"""
+from collections import Counter, deque
+
+
+def get_haffman_tree(s):
+    unique_symbols = Counter(s)
+    sorted_symbols = deque(sorted(unique_symbols.items(), key=lambda item: item[1]))
+
+    if len(sorted_symbols) > 1:
+        while len(sorted_symbols) > 1:
+            combined_weight = sorted_symbols[0][1] + sorted_symbols[1][1]
+            combined_node = {0: sorted_symbols.popleft()[0],
+                             1: sorted_symbols.popleft()[0]}
+
+            for i, symbol in enumerate(sorted_symbols):
+                if combined_weight > symbol[1]:
+                    continue
+                else:
+                    sorted_symbols.insert(i, (combined_node, combined_weight))
+                    break
+            else:
+                sorted_symbols.append((combined_node, combined_weight))
+
+    else:
+        combined_weight = sorted_symbols[0][1]
+        combined_node = {0: sorted_symbols.popleft()[0], 1: None}
+        sorted_symbols.append((combined_node, combined_weight))
+
+    return sorted_symbols[0][0]
+
+
+code_table = dict()
+
+
+def get_haffman_code(tree, path=''):
+    if not isinstance(tree, dict):
+        code_table[tree] = path
+    else:
+        get_haffman_code(tree[0], path=f'{path}0')
+        get_haffman_code(tree[1], path=f'{path}1')
+
+
+s = "на доме чемодан"
+
+haffman_tree = get_haffman_tree(s)
+get_haffman_code(haffman_tree)
+
+print(code_table)
+
+for i in s:
+    print(code_table[i], end=' ')

From 9b4d635caf02452a2bf2849c5b40fc37ee2279f9 Mon Sep 17 00:00:00 2001
From: v-v-d <v-v-d@bk.ru>
Date: Fri, 30 Aug 2019 01:23:32 +0300
Subject: [PATCH 2/2] task 2 done

---
 Lesson_8/2.py | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/Lesson_8/2.py b/Lesson_8/2.py
index ab731b29..4f3f489b 100644
--- a/Lesson_8/2.py
+++ b/Lesson_8/2.py
@@ -2,4 +2,19 @@
 2*. Определение количества различных подстрок с использованием хэш-функции.
 Пусть дана строка S длиной N, состоящая только из маленьких латинских букв.
 Требуется найти количество различных подстрок в этой строке.
-"""
\ No newline at end of file
+"""
+import random
+import hashlib
+
+n = random.randint(10, 50)
+first_ascii_num = 97
+last_ascii_num = 122
+
+s = ''.join([chr(random.randint(first_ascii_num, last_ascii_num)) for _ in range(n)])
+
+substrings = set()
+for i in range(len(s)):
+    for j in reversed(range(i + 1, len(s))):
+        substrings.add(hashlib.sha256(s[i:j].encode('UTF-8')).hexdigest())
+
+print(f'Количество различных подстрок в строке "{s}": {len(substrings)}')