Create count-the-number-of-special-characters-i.cpp

kamyu104 · Apr 21, 2024 · 70358e2 · 70358e2
1 parent 64ea4bf
commit 70358e2
Showing 1 changed file with 25 additions and 0 deletions.
diff --git a/C++/count-the-number-of-special-characters-i.cpp b/C++/count-the-number-of-special-characters-i.cpp
@@ -0,0 +1,25 @@
+// Time:  O(n + 26)
+// Space: O(26)
+
+// hash table
+class Solution {
+public:
+    int numberOfSpecialChars(string word) {
+        vector<bool> lookup1(26);
+        vector<bool> lookup2(26);
+        for (const auto& x : word) {
+            if (islower(x)) {
+                lookup1[x - 'a'] = true;
+            } else {
+                lookup2[x - 'A'] = true;
+            }
+        }
+        int result = 0;
+        for (int i = 0; i < 26; ++i) {
+            if (lookup1[i] == lookup2[i] && lookup2[i] == true) {
+                ++result;
+            }
+        }
+        return result;
+    }
+};