Create backspace_compare_strings.py

Author: avidLearnerInProgress

backspace_compare_strings.py

@@ -0,0 +1,42 @@
+class Solution:
+    def backspaceCompare(self, str1: str, str2: str) -> bool:
+
+      ptr1, ptr2 = len(str1) - 1, len(str2) - 1
+
+      while ptr1 >= 0 or ptr2 >= 0:
+        skipA, skipB = 0, 0
+
+        while ptr1 >= 0:
+          # counting a character two times // decrementing the pointer two times for every # that is encountered
+          if str1[ptr1] == '#':
+            skipA += 1
+            ptr1 -= 1
+          elif skipA > 0:
+            skipA -= 1
+            ptr1 -=1
+          # for a non-hash char when the skip is 0(no # encountered so far) - compare chars
+          else:
+            print("skipA", skipA, ptr1)
+            break
+
+        while ptr2 >= 0:
+          if str2[ptr2] == '#':
+            skipB += 1
+            ptr2 -= 1
+          elif skipB > 0:
+            skipB -= 1
+            ptr2 -= 1
+          else:
+            print("skipB", skipB, ptr2)
+            break
+        
+        if (ptr1 >= 0) != (ptr2 >= 0):
+          return False
+
+        if ptr1 >= 0 and ptr2 >= 0 and str1[ptr1] != str2[ptr2]:
+          return False
+
+        ptr1 -= 1
+        ptr2 -= 1
+
+      return True