text: In this loop we count the frequency of element through map m .
code: for ( int i = 0 ; i < n ; ++ i ) { if ( m . containsKey ( a [ i ] ) ) { int x = m . get ( a [ i ] ) + 1 ; m . put ( a [ i ] , x ) ; } else { m . put ( a [ i ] , 1 ) ; } }