Count words that appear exactly two times in an array of words | Java program to count all words with count exactly 2. ; Returns count of words with frequency exactly 2. ; Driver code
import java . util . HashMap ; import java . util . Map ; public class GFG { static int countWords ( String str [ ] , int n ) { HashMap < String , Integer > m = new HashMap < > ( ) ; for ( int i = 0 ; i < n ; i ++ ) { if ( m . containsKey ( str [ i ] ) ) { int get = m . get ( str [ i ] ) ; m . put ( str [ i ] , get + 1 ) ; } else { m . put ( str [ i ] , 1 ) ; } } int res = 0 ; for ( Map . Entry < String , Integer > it : m . entrySet ( ) ) { if ( it . getValue ( ) == 2 ) res ++ ; } return res ; } public static void main ( String args [ ] ) { String s [ ] = { " hate " , " love " , " peace " , " love " , " peace " , " hate " , " love " , " peace " , " love " , " peace " } ; int n = s . length ; System . out . println ( countWords ( s , n ) ) ; } }