Count of buttons pressed in a keypad mobile
Last Updated :
07 May, 2024
Given a string str, the task is to count how many times the keys will be pressed in total if there is a mobile like below image to form the given string.
Examples:Â
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Input: str = “abcdef”Â
Output: 12Â
1 for a, 2 for b, 3 for c, 1 for d, 2 for e and 3 for fÂ
Total = 1 + 2 + 3 + 1 + 2 + 3 = 12
Input: str = “ssss”Â
Output: 16Â
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Approach: Use an array to store how many times a button has to be pressed for typing a particular character and then traverse the given string character by character and add all the corresponding count of key presses to the sum variable.
Below is the implementation of the above approach:
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C++
// C++ implementation of the approach
#include <bits/stdc++.h>
using namespace std;
// Array to store how many times a button
// has to be pressed for typing
// a particular character
const int arr[] = { 1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3, 1,
2, 3, 1, 2, 3, 4, 1, 2, 3, 1, 2, 3, 4 };
// Function to return the count of
// buttons pressed to type the given string
int countKeyPressed(string str, int len)
{
int count = 0;
// Count the key presses
for (int i = 0; i < len; i++)
count = count + arr[str[i] - 'a'];
// Return the required count
return count;
}
// Driver code
int main()
{
string str = "abcdef";
int len = str.length();
cout << countKeyPressed(str, len);
return 0;
}
Java
// Java implementation of the approach
class GFG {
// Array to store how many times a button
// has to be pressed for typing
// a particular character
static final int arr[] = { 1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3, 1,
2, 3, 1, 2, 3, 4, 1, 2, 3, 1, 2, 3, 4 };
// Function to return the count of
// buttons pressed to type the given string
public static int countKeyPressed(String str, int len)
{
int count = 0;
// Count the key presses
for (int i = 0; i < len; i++)
count = count + arr[str.charAt(i) - 'a'];
// Return the required count
return count;
}
// Driver code
public static void main(String[] args)
{
String str = "abcdef";
int len = str.length();
System.out.print(countKeyPressed(str, len));
}
}
Python3
# Python3 implementation of the approach
# Array to store how many times a button
# has to be pressed for typing
# a particular character
arr = [ 1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3, 1,
2, 3, 1, 2, 3, 4, 1, 2, 3, 1, 2, 3, 4 ];
# Function to return the count of
# buttons pressed to type the given string
def countKeyPressed(string, length) :
count = 0;
# Count the key presses
for i in range(length) :
count += arr[ord(string[i]) - ord('a')];
# Return the required count
return count;
# Driver code
if __name__ == "__main__" :
string = "abcdef";
length = len(string);
print(countKeyPressed(string, length));
# This code is contributed by Ryuga
C#
// C# implementation of the approach
using System;
class GFG {
// Array to store how many times a button
// has to be pressed for typing
// a particular character
static readonly int[] arr = { 1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3, 1,
2, 3, 1, 2, 3, 4, 1, 2, 3, 1, 2, 3, 4 };
// Function to return the count of
// buttons pressed to type the given string
public static int countKeyPressed(String str, int len)
{
int count = 0;
// Count the key presses
for (int i = 0; i < len; i++)
count = count + arr[str[i] - 'a'];
// Return the required count
return count;
}
// Driver code
public static void Main()
{
String str = "abcdef";
int len = str.Length;
Console.Write(countKeyPressed(str, len));
}
}
Javascript
<script>
// Javascript implementation of the approach
// Array to store how many times a button
// has to be pressed for typing
// a particular character
var arr = [ 1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3, 1,
2, 3, 1, 2, 3, 4, 1, 2, 3, 1, 2, 3, 4 ]
// Function to return the count of
// buttons pressed to type the given string
function countKeyPressed(str, len)
{
var count = 0;
// Count the key presses
for (var i = 0; i < len; i++)
count = count + arr[str.charCodeAt(i) - 97];
// Return the required count
return count;
}
// Driver code
var str = "abcdef";
var len = str.length;
document.write(countKeyPressed(str, len));
// This code is contributed by noob2000.
</script>
PHP
<?php
// PHP implementation of the approach
// Array to store how many times a
// button has to be pressed for
// typing a particular character
$arr = array( 1, 2, 3, 1, 2, 3,
1, 2, 3, 1, 2, 3, 1,
2, 3, 1, 2, 3, 4, 1,
2, 3, 1, 2, 3, 4 );
// Function to return the count of
// buttons pressed to type the given string
function countKeyPressed($str, $len)
{
global $arr;
$count = 0;
// Count the key presses
for ($i = 0; $i < $len; $i++)
$count = $count + $arr[ord($str[$i]) -
ord('a')];
// Return the required count
return $count;
}
// Driver code
$str = "abcdef";
$len = strlen($str);
echo countKeyPressed($str, $len);
// This code is contributed by ita_c
?>
Time Complexity: O(n)
Auxiliary Space: O(1)
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