CountVowelRecursive

Author: jbhattac

CountVowelRecursive.java

@@ -0,0 +1,22 @@
+package ds.algo.solutions;
+
+public class CountVowelRecursive {
+
+	public static void main(String[] args) {
+		
+		String str = "hello world";
+		System.out.println(countVowels(str, str.length() - 1));
+	}
+
+	private static boolean isVowel(char ch) {
+		return ch == 'A' || ch == 'E' || ch == 'I' || ch == 'O' || ch == 'U' || 
+				ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u';
+	}
+	
+	private static int countVowels(String str, int pos) {
+		if (pos == 1)
+			return isVowel(str.charAt(pos - 1)) ? 1 : 0;
+		
+		return countVowels(str, pos - 1) + (isVowel(str.charAt(pos - 1)) ? 1 : 0);
+	}
+}