9612번: Maximum Word Frequency

문제 출처 : https://www.acmicpc.net/problem/9612

 

언어 : Kotlin

 

문제 설명 :

Term frequency–Inverse document frequency (tf-idf) is a numerical statistic which reflects the importance of words in a document collection. It is often used in information retrieval system. The number of times a word appears in the document (word frequency) is one of the major factors to acquire tf-idf. 

You are asked to write a program to find the most frequent word in a document. 

 

입력 :

The first line contains an integer n (1≤ n ≤ 1000) which determines the number of words. The following n lines include the list of words, one word per line. A word contains only lower-case letters and it can contain up to 20 characters. 

 

출력 :

Print out the word that has the highest frequency and its frequency, separated by a single space. If you get more than 2 results, choose only the one that comes later in the lexicographical order. 

 

제한 사항 :

• 시간 제한 : 1초
• 메모리 제한 : 128MB

 

입출력 예 :

입력	출력
10 mountain lake lake zebra tree lake zebra zebra animal lakes	zebra 3

 

풀이 : 

import java.io.BufferedWriter
import java.io.OutputStreamWriter

fun main() = with(System.`in`.bufferedReader()) {
    val bw = BufferedWriter(OutputStreamWriter(System.out))

    val words = Array<String>(readLine().toInt()) { readLine() }
        .groupingBy { it }
        .eachCount()
        .maxBy { it.key }
    
    bw.write("${words.key} ${words.value}")
    bw.flush()
    bw.close()
}