Problem resolved in Wanderlog Assesments for Software Engineer role.

For a given array of transactions, group all of the transactions by item name. Return an array of strings where each string contains the item name followed by a space and the number of associated transactions.

Note: Sort the array descending by transaction count, then ascending alphabetically by item name for items with matching transaction counts.

Example:

transactions = ['notebook', 'notebook', 'mouse', 'keyboard', 'mouse']

There are two items with 2 transactions each: 'notebook' and 'mouse'. In alphabetical order, they are 'mouse', 'notebook'.

There is one item with 1 transaction: 'keyboard'.

The return array, sorted as required, is ['mouse 2', 'notebook 2', 'keyboard 1'].

Function Description

Complete the function groupTransactions in the editor below.

groupTransactions has the following parameter(s):

• string transactions[n]: each transactions[i] denotes the item name in the i^th^ transaction

Returns:

• string[]: an array of strings of "item name[space]transaction count" sorted as described

Constraints:

• 1 ≤ n ≤ 10^5^
• 1 ≤ length of transactions[i] ≤ 10
• transactions[i] contains only lowercase English letters, ascii[a-z]

Input Format for Custom Testing

Input from stdin will be processed as follows and passed to the function.

• The first line contains a single integer, n, the size of transactions.
• Each of the next n lines contains a string, the item name for transactions[i].

Sample Input

STDIN     Function
-----     -----
4      →  transactions[] size n = 4
bin    →  transactions = ['bin', 'can', 'bin', 'bin']
can
bin
bin

Sample Output

bin 3
can 1

Explanation:

• There is one item 'bin' with 3 transactions.
• There is one item 'can' with 1 transaction.
• The return array sorted descending by transaction count, then ascending by name is ['bin 3', 'can 1'].

Sample Input

STDIN     Function
-----     -----
3      →  transactions[] size n = 3
banana →  transactions = ['banana', 'pear', 'apple']
pear
apple

Sample Output

apple 1
banana 1
pear 1

Explanation:

• There is one item 'apple' with 1 transaction.
• There is one item 'banana' with 1 transaction.
• There is one item 'pear' with 1 transaction.
• The return array sorted descending by transaction count, then ascending by name is ['apple 1', 'banana 1', 'pear 1'].