Frequency Measuring Techniques for Competitive Programming | Java program to count frequencies of array items ; Mark all array elements as not visited ; Traverse through array elements and count frequencies ; Skip this element if already processed ; Count frequency ; Driver Code
import java . util . * ; class GFG { static void countFreq ( int arr [ ] , int n ) { boolean [ ] visited = new boolean [ n ] ; for ( int i = 0 ; i < n ; i ++ ) { if ( visited [ i ] == true ) continue ; int count = 1 ; for ( int j = i + 1 ; j < n ; j ++ ) { if ( arr [ i ] == arr [ j ] ) { visited [ j ] = true ; count ++ ; } } System . out . println ( arr [ i ] + " ▁ " + count ) ; } } public static void main ( String [ ] args ) { int arr [ ] = { 10 , 20 , 20 , 10 , 10 , 20 , 5 , 20 } ; int n = arr . length ; countFreq ( arr , n ) ; } }