Add permutation in string

Author: onixlas

sliding-window/567_Permutation_in_String/solution.py

@@ -0,0 +1,38 @@
+def check_inclusion(s1: str, s2: str) -> bool:
+    pattern_hash = {}
+    for character in s1:
+        if character not in pattern_hash:
+            pattern_hash[character] = 1
+        else:
+            pattern_hash[character] += 1
+
+    hash_copy = pattern_hash.copy()
+    pattern_length = len(s1)
+
+    for index in range(len(s2)):
+        if index >= pattern_length:
+            outgoing_character = s2[index - pattern_length]
+            if outgoing_character in pattern_hash:
+                if outgoing_character not in hash_copy:
+                    hash_copy[outgoing_character] = 1
+                else:
+                    hash_copy[outgoing_character] += 1
+                if hash_copy[outgoing_character] == 0:
+                    del hash_copy[outgoing_character]
+
+        incoming_character = s2[index]
+        if incoming_character in pattern_hash:
+            if incoming_character in hash_copy:
+                hash_copy[incoming_character] -= 1
+            else:
+                hash_copy[incoming_character] = -1
+            if hash_copy[incoming_character] == 0:
+                del hash_copy[incoming_character]
+            if len(hash_copy) == 0:
+                return True
+    return False
+
+
+assert check_inclusion(s1='ab', s2='eidbaooo') == True, 'Test 1 Failed'
+assert check_inclusion(s1='ab', s2='eidboaoo') == False, 'Test 2 Failed'
+assert check_inclusion(s1='adc', s2='dcda') == True, 'Test 3 Failed'