leetcode count # of special characters

leetcode/algorithms/easy/count_the_number_of_special_characters.py

@@ -0,0 +1,19 @@
+class Solution:
+    def numberOfSpecialChars(self, word: str) -> int:
+        s, d = set(), {}
+        for e in word:
+            if e in s:
+                continue
+            s.add(e)
+            v = e.lower()
+            if v in d:
+                if v == e:
+                    d[v] -= 1
+                else:
+                    d[v] += 1
+            else:
+                if v == e:
+                    d[v] = -1
+                else:
+                    d[v] = 1
+        return sum(v == 0 for v in d.values())