LeetCode 1544. Make The String Great

Author: raul-sauco

README.md

@@ -299,6 +299,7 @@ Solutions to LeetCode problems. The first column links to the problem in LeetCod
 | [1465. Maximum Area of a Piece of Cake After Cuts][lc1465]                     | 🟠 Medium  | [![python](res/py.png)][lc1465py]                                                   |
 | [1473. Paint House III][lc1473]                                                | 🔴 Hard    | [![python](res/py.png)][lc1473py]                                                   |
 | [1480. Running Sum of 1d Array][lc1480]                                        | 🟢 Easy    | [![python](res/py.png)][lc1480py]                                                   |
+| [1544. Make The String Great][lc1544]                                          | 🟢 Easy    | [![python](res/py.png)][lc1544py]                                                   |
 | [1578. Minimum Time to Make Rope Colorful][lc1578]                             | 🟠 Medium  | [![python](res/py.png)][lc1578py]                                                   |
 | [1584. Min Cost to Connect All Points][lc1584]                                 | 🟠 Medium  | [![python](res/py.png)][lc1584py]                                                   |
 | [1603. Design Parking System][lc1603]                                          | 🟢 Easy    | [![python](res/py.png)][lc1603py]                                                   |
@@ -894,6 +895,8 @@ Solutions to LeetCode problems. The first column links to the problem in LeetCod
 [lc1473py]: leetcode/paint-house-iii.py
 [lc1480]: https://leetcode.com/problems/running-sum-of-1d-array/
 [lc1480py]: leetcode/running_sum.py
+[lc1544]: https://leetcode.com/problems/make-the-string-great/
+[lc1544py]: leetcode/make-the-string-great.py
 [lc1578]: https://leetcode.com/problems/minimum-time-to-make-rope-colorful/
 [lc1578py]: leetcode/minimum-time-to-make-rope-colorful.py
 [lc1584]: https://leetcode.com/problems/min-cost-to-connect-all-points/

leetcode/make-the-string-great.py

@@ -0,0 +1,86 @@
+# 1544. Make The String Great
+# 🟢 Easy
+#
+# https://leetcode.com/problems/make-the-string-great/
+#
+# Tags: String - Stack
+
+import timeit
+
+
+# Iterate over the elements of the input string pushing them into a
+# stack, if the element that we visit is the uppercase or lowercase
+# counterpart of the last element on the stack, pop that element.
+#
+# Time complexity: O(n) - Where n is the number of characters in the
+# input.
+# Space complexity: O(n) - The stack could have n elements where n is
+# the number of characters of the input.
+#
+# Runtime: 53 ms, faster than 76.90%
+# Memory Usage: 13.8 MB, less than 61.93%
+class StackPushPop:
+    def makeGood(self, s: str) -> str:
+        stack = []
+        for c in s:
+            if stack and (
+                (c.islower() and c.upper() == stack[-1])
+                or (c.isupper() and c.lower() == stack[-1])
+            ):
+                stack.pop()
+            else:
+                stack.append(c)
+        return "".join(stack)
+
+
+# Similar approach but simplify the if statement using character's ASCII
+# values.
+#
+# Time complexity: O(n) - Where n is the number of characters in the
+# input.
+# Space complexity: O(n) - The stack could have n elements where n is
+# the number of characters of the input.
+#
+# Runtime: 24 ms, faster than 99.91%
+# Memory Usage: 13.8 MB, less than 61.93%
+class StackAndOrd:
+    def makeGood(self, s: str) -> str:
+        stack = []
+        for c in s:
+            if stack and abs(ord(c) - ord(stack[-1])) == 32:
+                stack.pop()
+            else:
+                stack.append(c)
+        return "".join(stack)
+
+
+def test():
+    executors = [
+        StackPushPop,
+        StackAndOrd,
+    ]
+    tests = [
+        ["s", "s"],
+        ["Pp", ""],
+        ["abBAcC", ""],
+        ["leEeetcode", "leetcode"],
+    ]
+    for executor in executors:
+        start = timeit.default_timer()
+        for _ in range(1):
+            for col, t in enumerate(tests):
+                sol = executor()
+                result = sol.makeGood(t[0])
+                exp = t[1]
+                assert result == exp, (
+                    f"\033[93m» {result} <> {exp}\033[91m for"
+                    + f" test {col} using \033[1m{executor.__name__}"
+                )
+        stop = timeit.default_timer()
+        used = str(round(stop - start, 5))
+        cols = "{0:20}{1:10}{2:10}"
+        res = cols.format(executor.__name__, used, "seconds")
+        print(f"\033[92m» {res}\033[0m")
+
+
+test()