Create 1456-maximum-number-of-vowels-in-a-substring-of-given-length.cpp

Author: Abe0770

cpp/1456-maximum-number-of-vowels-in-a-substring-of-given-length.cpp

@@ -0,0 +1,45 @@
+/*
+  Given a string s and an integer k, return the maximum number of vowel letters in any substring of s with length k.
+  Vowel letters in English are 'a', 'e', 'i', 'o', and 'u'.
+
+  Ex.
+  Input: s = "abciiidef", k = 3
+  Output: 3
+  Explanation: The substring "iii" contains 3 vowel letters.
+
+  Approach : Sliding Window
+
+  Time  : O(N)
+  Space : O(1)
+*/
+
+
+class Solution {
+public:
+    bool isVowel(char ch) {
+        if(ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u') 
+            return true;
+        return false;
+    }
+    int maxVowels(string s, int k) {
+        int ptr1 = 0, ptr2 = 0, count = 0, maxi = INT_MIN;
+        while(ptr2 < s.size()) {
+            if(ptr2 - ptr1 == k) {
+                maxi = max(count, maxi);
+                if(maxi == k)
+                    return count;
+                if(isVowel(s[ptr1++]))
+                    count--;
+                if(isVowel(s[ptr2++]))
+                    count++;
+
+            } else {
+                if(isVowel(s[ptr2]))
+                    count++;
+                ptr2++;
+            }
+        }
+        maxi = max(count, maxi);
+        return maxi;
+    }
+};