diff --git a/algocode/hash_tables/3sum.py b/algocode/hash_tables/3sum.py
new file mode 100644
index 0000000..ea74cf4
--- /dev/null
+++ b/algocode/hash_tables/3sum.py
@@ -0,0 +1,36 @@
+from typing import List
+
+class Solution:
+    def threeSum(self, nums: List[int]) -> List[List[int]]:
+        sorted = nums.sort()
+        result = []
+        for i in range(0, len(nums) - 2):
+            if i > 0 and nums[i] == nums[i-1]:
+                i += 1
+                continue
+            j = i + 1
+            k = len(nums) - 1
+            first_num = nums[i]
+            while j < k:
+                second_num = nums[j]
+                third_num = nums[k]
+                tmp_sum = first_num + second_num + third_num
+                if tmp_sum < 0:
+                    j += 1
+                elif tmp_sum > 0:
+                    k -= 1
+                elif tmp_sum == 0:
+                    j += 1
+                    result.append([first_num, second_num, third_num])
+                    while nums[j-1] == nums[j] and j < k:
+                        j += 1
+                else:
+                    raise ValueError("Some strange shit happened")
+            i += 1
+        return result
+
+
+cl = Solution()
+print(cl.threeSum(nums=[-1,0,1,2,-1,4]))
+print(cl.threeSum(nums=[0,0,0]))
+print(cl.threeSum(nums=[0,0,0,0]))
diff --git a/algocode/hash_tables/isomorphic_strings.py b/algocode/hash_tables/isomorphic_strings.py
new file mode 100644
index 0000000..349caca
--- /dev/null
+++ b/algocode/hash_tables/isomorphic_strings.py
@@ -0,0 +1,74 @@
+class Solution:
+    def isIsomorphic(self, s: str, t: str) -> bool:
+        res = {}
+        already_mapped = set()
+        for i in range(0, len(s)):
+            s_word = s[i]
+            t_word = t[i]
+            if t_word in already_mapped and s_word not in res:
+                return False
+            match = res.get(s_word)
+            # Если не встречался символ
+            if not match:
+                # Пока слова изоморфны - мапим новую пару
+                res[s_word] = t_word
+                already_mapped.add(t_word)
+                continue
+            if match != t_word:
+                return False
+            already_mapped.add(t_word)
+        # Если массив закончился и не было возврата False => слова изоморфны
+        return True
+
+
+"""
+STEP 1 
+s = "badc"
+t = "baba"
+
+res = {}
+match = None
+res = {"b": "b"}
+
+STEP 2 
+s = "badc"
+t = "baba"
+
+res = {"b": "b"}
+match = None
+res = {"b": "b", "a":"a"}
+
+STEP 3 
+s = "badc"
+t = "baba"
+
+res = {"b": "b", "a":"a"}
+match = None
+res = {"b": "b", "a":"a", "d": "b"} <- Тут двойной маппинг => надо еще вести уже замапленые символы из t
+"""
+
+cl = Solution()
+# s = "egg"
+# t = "add"
+# print(cl.isIsomorphic(s, t))
+#
+# s = "foo"
+# t = "bar"
+# print(cl.isIsomorphic(s, t))
+#
+# s = "paper"
+# t = "title"
+# print(cl.isIsomorphic(s, t))
+#
+#
+# s = "p"
+# t = "t"
+# print(cl.isIsomorphic(s, t))
+#
+# s = "p"
+# t = "p"
+# print(cl.isIsomorphic(s, t))
+
+s = "badc"
+t = "baba"
+print(cl.isIsomorphic(s, t))
diff --git a/algocode/two_pointers/unurlify.py b/algocode/two_pointers/unurlify.py
new file mode 100644
index 0000000..d08441a
--- /dev/null
+++ b/algocode/two_pointers/unurlify.py
@@ -0,0 +1,86 @@
+"""
+Дан список s. Нужно заменить все вхождения %20 на пробелы в списке s, а оставшиеся лишние символы заменить на #, сохранив длину списка. В качестве ответа верни изменённый список s.
+
+Пример 1:
+
+Ввод: s = ["h","e","l","l","o","%","2","0","w","o","r","l","d"]
+Вывод: ["h","e","l","l","o"," ","w","o","r","l","d","#","#"]
+Пример 2:
+
+Ввод: s = ["a","%","2","0","b","%","2","0","%","2","0", "c"]
+Вывод: ["a"," ","b"," ", " ", "c","#","#","#","#","#","#"]
+Ограничения:
+
+len(s) >= 1
+"""
+
+from typing import List
+
+
+def solve(s: List[str]) -> List[str]:
+    i, j = 0, 0
+    s_len = len(s)
+    for i in range(0, s_len):
+        if j >= s_len:
+            while i < s_len:
+                s[i] = "#"
+                i += 1
+            break
+        s[i] = s[j]
+        if s[i] == "%":
+            s[i] = " "
+            j += 3
+            i += 1
+        else:
+            i += 1
+            j += 1
+    return s
+
+
+print(solve(s=["h", "e", "l", "l", "o", "%", "2", "0", "w", "o", "r", "l", "d"]))
+print(solve(s=["a", "%", "2", "0", "b", "%", "2", "0", "%", "2", "0", "c"]))
+
+#  i
+# "a","%","2","0","b","%","2","0","%","2","0", "c"
+#  j
+#
+# --- i+=1 j+=1 ---
+#
+#      i
+# "a","%","2","0","b","%","2","0","%","2","0", "c"
+#      j
+#
+# Заменяем процент на пробел
+#
+# --- i+=1 j+=3 ---
+#
+#          i
+# "a"," ","2","0","b","%","2","0","%","2","0", "c"
+#                  j
+#
+# --- i+=1 j+=1 ---
+#
+#              i
+# "a"," ","b","0","b","%","2","0","%","2","0", "c"
+#                      j
+# Замена s[i] = s[j] приводит к процентной итерации
+#
+# --- i+=1 j+=3 ---
+#
+#                  i
+# "a"," ","b"," ","b","%","2","0","%","2","0", "c"
+#                                  j
+#
+# Замена s[i] = s[j] приводит к процентной итерации
+#
+# --- i+=1 j+=3 ---
+#
+#                      i
+# "a"," ","b"," "," ","%","2","0","%","2","0", "c"
+#                                               j
+#
+# --- i+=1 j+=1 ---
+#
+#                          i
+# "a"," ","b"," "," ","c","2","0","%","2","0", "c"
+#                                                   j