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Process Logs

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Problem statement

Application logs are useful in analyzing interaction with an application and may also be used to detect suspicious activities.

A log file is provided as a string array where each entry represents a money transfer in the form "sender_user_id recipient_user_id amount". Each of the values is separated by a space.

- sender_user_id and recipient_user_id both consist only of digits, are at most 9 digits long and start with non-zero digit

- amount consists only of digits, is at most 9 digits long and starts with non-zero digit

Logs are given in no particular order. Write a function that returns an array of strings denoting user_id's of suspicious users who were involved in at least threshold number of log entries. The id's should be ordered ascending by numeric value.

Function

processLogs(logs: String[], threshold: int) → String[]

Complete the function processLogs in the editor.

The function has the following parameter(s):

  1. 1. String logs[n]: each logs[i] denotes the i’th entry in the logs
  2. 2. int threshold: the minimum number of transactions that a user must have to be included in the result

Returns

String[]: an array of user id's as strings, sorted ascending by numeric value

Examples

Example 1

logs = ["88 99 200", "88 99 300", "99 32 100", "12 12 15"]threshold = 2return = ["88", "99"]

There are two users with at least threshold = 2 transactions: 99 and 88. In ascending order, the return array is ['88', '99'].

Note: In the last log entry, user 12 was on both sides of the transaction. This counts as only 1 transaction for user 12.

Constraints

  • 1 ≤ n ≤ 10^5
  • 1 ≤ threshold ≤ n
  • The sender_user_id, recipient_user_id and amount contain only characters in the range ascii["0"-"9"].
  • The sender_user_id, recipient_user_id and amount start with a non-zero digit.
  • 0 < length of sender_user_id, recipient_user_id, amount ≤ 9.
  • The result will contain at least one element.

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public String[] processLogs(String[] logs, int threshold) {
  // write your code here
}
logs["88 99 200", "88 99 300", "99 32 100", "12 12 15"]
threshold2
expected["88", "99"]
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