925. Long Pressed Name

    - Language: Python.
    - Time complexity: O(n+m).
    - Space complexity: O(1).
    - Solution:
        https://leetcode.com/problems/long-pressed-name/editorial/

Author: welder87

python_solutions/lc_925_long_pressed_name/lc_925.py

@@ -27,3 +27,33 @@ def isLongPressedNameV1(self, name, typed):
             return False
 
         return all(k1 == k2 and v1 <= v2 for (k1, v1), (k2, v2) in zip(g1, g2))
+
+    def isLongPressedNameV2(self, name: str, typed: str) -> bool:
+        # Time complexity: O(n + m). Space complexity: O(1).
+        # Solution: https://leetcode.com/problems/long-pressed-name/editorial/
+        # two pointers to the "name" and "typed" string respectively
+        np, tp = 0, 0
+        # advance two pointers, until we exhaust one of the strings
+        while np < len(name) and tp < len(typed):
+            if name[np] == typed[tp]:
+                np += 1
+                tp += 1
+            elif tp >= 1 and typed[tp] == typed[tp - 1]:
+                tp += 1
+            else:
+                return False
+        # if there is still some characters left *unmatched* in the origin string,
+        #   then we don't have a match.
+        # e.g.  name = "abc"  typed = "aabb"
+        if np != len(name):
+            return False
+        else:
+            # In the case that there are some redundant characters left in typed
+            # we could still have a match.
+            # e.g.  name = "abc"  typed = "abccccc"
+            while tp < len(typed):
+                if typed[tp] != typed[tp - 1]:
+                    return False
+                tp += 1
+        # both strings have been consumed
+        return True

python_solutions/lc_925_long_pressed_name/test_lc_925.py

@@ -34,6 +34,11 @@ def test_success_v1(name: str, typed: str, ans: bool, solution: Solution):
     assert solution.isLongPressedNameV1(name, typed) is ans
 
 
+@pytest.mark.parametrize(("name", "typed", "ans"), test_cases)
+def test_success_v2(name: str, typed: str, ans: bool, solution: Solution):
+    assert solution.isLongPressedNameV2(name, typed) is ans
+
+
 @pytest.fixture
 def solution() -> Solution:
     return Solution()