Create smartkeypad2.java

Take as input str, a string. str represents keys pressed on a nokia phone keypad. We are concerned with all possible words that can be written with the pressed keys.

Assume the following alphabets on the keys: 1 -> abc , 2 -> def , 3 -> ghi , 4 -> jkl , 5 -> mno , 6 -> pqrs , 7 -> tuv , 8 -> wx , 9 -> yz

E.g. “12” can produce following words “ad”, “ae”, “af”, “bd”, “be”, “bf”, “cd”, “ce”, “cf”

a. Write a recursive function which returns the count of words for a given keypad string. Print the value returned.

b.Write a recursive function which prints all possible words for a given keypad string (void is the return type for function).

Input Format
Single line input containing a single integer.

Constraints
1 <= Length of string <= 10^3

Output Format
Print all the words in a space separated manner. Also print the count of these numbers in next line.

Sample Input
12
Sample Output
ad ae af bd be bf cd ce cf
9
Explanation
1 can correspond to 'a' , 'b' or 'c' .
2 can correspond to 'd', 'e' or 'f'.
We print all combinations of these

Author: Gopal868484

Recursion/smartkeypad2.java

@@ -0,0 +1,35 @@
+import java.util.*;
+public class Main {
+    static int count = 0;
+    static String[] mapping = { "", "abc", "def", "ghi", "jkl", "mno", "pqrs", "tuv", "wx","yz" };
+
+    	public static void keypad(String digits, String comb) {
+
+		if (digits.length() == 0) {
+            count++;
+			System.out.print(comb+" ");
+			return;
+		}
+		char digitPressed = digits.charAt(0);
+		int index = digitPressed - '0';
+
+		String mappedString = mapping[index];
+
+		for (int i = 0; i < mappedString.length(); i++) {
+
+			String leftString = digits.substring(1);
+			char choice = mappedString.charAt(i);
+			keypad(leftString, comb + choice);
+		}
+
+	}
+    
+    
+    public static void main(String args[]) {
+        Scanner sc = new Scanner(System.in);
+        String str = sc.nextLine();
+        keypad(str,"");
+        System.out.println();
+        System.out.println(count);
+    }
+}