static boolean isValidString ( String str ) {
  int freq [ ] = new int [ CHARS ] ;
  for ( int i = 0 ;
  i < str . length ( ) ;
  i ++ ) {
    freq [ str . charAt ( i ) - 'a' ] ++ ;
  }
  int i , freq1 = 0 , count_freq1 = 0 ;
  for ( i = 0 ;
  i < CHARS ;
  i ++ ) {
    if ( freq [ i ] != 0 ) {
      freq1 = freq [ i ] ;
      count_freq1 = 1 ;
      break ;
    }
  }
  int j , freq2 = 0 , count_freq2 = 0 ;
  for ( j = i + 1 ;
  j < CHARS ;
  j ++ ) {
    if ( freq [ j ] != 0 ) {
      if ( freq [ j ] == freq1 ) {
        count_freq1 ++ ;
      }
      else {
        count_freq2 = 1 ;
        freq2 = freq [ j ] ;
        break ;
      }
    }
  }
  for ( int k = j + 1 ;
  k < CHARS ;
  k ++ ) {
    if ( freq [ k ] != 0 ) {
      if ( freq [ k ] == freq1 ) {
        count_freq1 ++ ;
      }
      if ( freq [ k ] == freq2 ) {
        count_freq2 ++ ;
      }
      else {
        return false ;
      }
    }
    if ( count_freq1 > 1 && count_freq2 > 1 ) {
      return false ;
    }
  }
  return true ;
}

static boolean isValidString ( String str ) { int freq [ ] = new int [ CHARS ] ; for ( int i = 0 ; i < str . length ( ) ; i ++ ) { freq [ str . charAt ( i ) - ' a ' ] ++ ; } int i , freq1 = 0 , count_freq1 = 0 ; for ( i = 0 ; i < CHARS ; i ++ ) { if ( freq [ i ] != 0 ) { freq1 = freq [ i ] ; count_freq1 = 1 ; break ; } } int j , freq2 = 0 , count_freq2 = 0 ; for ( j = i + 1 ; j < CHARS ; j ++ ) { if ( freq [ j ] != 0 ) { if ( freq [ j ] == freq1 ) { count_freq1 ++ ; } else { count_freq2 = 1 ; freq2 = freq [ j ] ; break ; } } } for ( int k = j + 1 ; k < CHARS ; k ++ ) { if ( freq [ k ] != 0 ) { if ( freq [ k ] == freq1 ) { count_freq1 ++ ; } if ( freq [ k ] == freq2 ) { count_freq2 ++ ; } else { return false ; } } if ( count_freq1 > 1 && count_freq2 > 1 ) { return false ; } } return true ; }
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