Convert a sentence into its equivalent mobile numeric keypad sequence

Given a sentence in the form of a string, convert it into its equivalent mobile numeric keypad sequence. 

Examples :

Input: GEEKSFORGEEKS
Output: 4333355777733366677743333557777
Explanation: For obtaining a number, we need to press a number corresponding to that character for a number of times equal to the position of the character. For example, for character E, press number 3 two times and accordingly.

Input : HELLO WORLD
Output : 4433555555666096667775553

Approach: Follow the steps given below to convert a sentence into its equivalent mobile numeric keypad sequence. 

• For each character, store the sequence which should be obtained at its respective position in an array, i.e. for Z, store 9999. For Y, store 999. For K, store 55 and so on.
• For each character, subtract ASCII value of ‘A’ and obtain the position in the array pointed 
  by that character and add the sequence stored in that array to a string.
• If the character is a space, store 0
• Print the overall sequence.

Below is the implementation of above method : 

C++

// C++ implementation to convert a
// sentence into its equivalent
// mobile numeric keypad sequence
#include <bits/stdc++.h>
using namespace std;

// Function which computes the sequence
string printSequence(string arr[], string input)
{
    string output = "";

    // length of input string
    int n = input.length();
    for (int i = 0; i < n; i++) {
        // Checking for space
        if (input[i] == ' ')
            output = output + "0";

        else {
            // Calculating index for each
            // character
            int position = input[i] - 'A';
            output = output + arr[position];
        }
    }

    // Output sequence
    return output;
}

// Driver Code
int main()
{
    // storing the sequence in array
    string str[]
        = { "2",   "22",  "222", "3",   "33",   "333", "4",
            "44",  "444", "5",   "55",  "555",  "6",   "66",
            "666", "7",   "77",  "777", "7777", "8",   "88",
            "888", "9",   "99",  "999", "9999" };

    string input = "GEEKSFORGEEKS";
    cout << printSequence(str, input);
    return 0;
}

Java

// Java implementation to convert a
// sentence into its equivalent
// mobile numeric keypad sequence
import java.util.*;

class GFG {

    // Function which computes the sequence
    static String printSequence(String arr[], String input)
    {
        String output = "";

        // length of input string
        int n = input.length();
        for (int i = 0; i < n; i++) {
            // Checking for space
            if (input.charAt(i) == ' ')
                output = output + "0";

            else {
                // Calculating index for each
                // character
                int position = input.charAt(i) - 'A';
                output = output + arr[position];
            }
        }

        // Output sequence
        return output;
    }

    // Driver Code
    public static void main(String[] args)
    {
        // storing the sequence in array
        String str[]
            = { "2",    "22",  "222", "3",   "33", "333",
                "4",    "44",  "444", "5",   "55", "555",
                "6",    "66",  "666", "7",   "77", "777",
                "7777", "8",   "88",  "888", "9",  "99",
                "999",  "9999" };

        String input = "GEEKSFORGEEKS";
        System.out.println(printSequence(str, input));
    }
}

// This code is contributed by Gitanjali.

Python3

# Python3 implementation to convert
# a sentence into its equivalent
# mobile numeric keypad sequence

# Function which computes the
# sequence


def printSequence(arr, input):

    # length of input string
    n = len(input)
    output = ""

    for i in range(n):

        # checking for space
        if(input[i] == ' '):
            output = output + "0"
        else:
            # calculating index for each
            # character
            position = ord(input[i]) - ord('A')
            output = output + arr[position]
    # output sequence
    return output


# Driver code
str = ["2", "22", "222",
       "3", "33", "333",
       "4", "44", "444",
       "5", "55", "555",
       "6", "66", "666",
       "7", "77", "777", "7777",
       "8", "88", "888",
       "9", "99", "999", "9999"]

input = "GEEKSFORGEEKS"
print(printSequence(str, input))

# This code is contributed by upendra bartwal

C#

// C# implementation to convert a
// sentence into its equivalent
// mobile numeric keypad sequence
using System;

class GFG {

    // Function which computes the sequence
    static String printSequence(string[] arr, string input)
    {
        string output = "";

        // length of input string
        int n = input.Length;
        for (int i = 0; i < n; i++) {
            // Checking for space
            if (input[i] == ' ')
                output = output + "0";

            else {
                // Calculating index for each
                // character
                int position = input[i] - 'A';
                output = output + arr[position];
            }
        }

        // Output sequence
        return output;
    }

    // Driver Code
    public static void Main()
    {
        // storing the sequence in array
        string[] str
            = { "2",    "22",  "222", "3",   "33", "333",
                "4",    "44",  "444", "5",   "55", "555",
                "6",    "66",  "666", "7",   "77", "777",
                "7777", "8",   "88",  "888", "9",  "99",
                "999",  "9999" };

        string input = "GEEKSFORGEEKS";
        Console.WriteLine(printSequence(str, input));
    }
}

// This code is contributed by vt_m.

PHP

<?php
// PHP implementation to convert a
// sentence into its equivalent
// mobile numeric keypad sequence

// Function which computes the sequence
function printSequence(&$arr, $input)
{
    $output = "";

    // length of input string
    $n = strlen($input);
    for ($i = 0; $i < $n; $i++)
    {
        // Checking for space
        if ($input[$i] == ' ')
            $output = $output + "0";

        else
        {
            // Calculating index for each
            // character
            $position = ord($input[$i]) - ord('A');
            $output = $output . $arr[$position];
        }
    }

    // Output sequence
    return $output;
}

// Driver Code

// storing the sequence in array
$str = array("2","22","222", "3","33","333",
             "4","44","444", "5","55","555",
             "6","66","666", "7","77","777","7777",
             "8","88","888", "9","99","999","9999");

$input = "GEEKSFORGEEKS";
echo printSequence($str, $input);

// This code is contributed by ita_c
?>

Javascript

<script>

// Javascript implementation to convert a
// sentence into its equivalent
// mobile numeric keypad sequence

    // Function which computes the sequence
    function printSequence(arr,input)
    {
        let output = "";

        // length of input string
        let n = input.length;
        for (let i = 0; i < n; i++)
        {
            // Checking for space
            if (input[i] == ' ')
                output = output + "0".charCodeAt(0);

            else
            {
                // Calculating index for each
                // character
                let position = input[i].charCodeAt(0) - 'A'.charCodeAt(0);
                output = output + arr[position];
            }
        }

        // Output sequence
        return output;
    }

    // Driver Function
    let str = ["2", "22", "222",
       "3", "33", "333",
       "4", "44", "444",
       "5", "55", "555",
       "6", "66", "666",
       "7", "77", "777", "7777",
       "8", "88", "888",
       "9", "99", "999", "9999" ]

    let input = "GEEKSFORGEEKS";
    document.write(printSequence(str, input));

    // This code is contributed by avanitrachhadiya2155
</script>

Output

4333355777733366677743333557777

Time complexity: O(N), For traversing the string
Auxiliary Space: O(N), For storing the answer.