Using the uml graphical notation for object classes, design the following object classes, identifying attributes and operations. use your own experience to decide on the attributes and operations that should be associated with these objects. a messaging system on a mobile (cell) phone or tablet a printer for a personal computer a personal music system a bank account a library catalog

Write a method replacekey in the minheap class with the following signature: public void replacekey(integer oldkey, integer newkey) the method will replace the first occurrence of oldkey with the newkey, and restore the min-heap property after the change. if the oldkey does not exist in the heap, the method prints an appropriate message and returns without changing the heap. example: suppose our binary heap object (bh) has the following keys: *** 4 6 7 32 19 64 26 99 42 54 28 then the method call: bh.replacekey (oldkey integer(54), newkey integer(2))

Consider this data sequence: "3 11 5 5 5 2 4 6 6 7 3 -8". any value that is the same as the immediately preceding value is considered a consecutive duplicate. in this example, there are three such consecutive duplicates: the 2nd and 3rd 5s and the second 6. note that the last 3 is not a consecutive duplicate because it was preceded by a 7. write some code that uses a loop to read such a sequence of non-negative integers , terminated by a negative number. when the code finishes executing, the number of consecutive duplicates encountered is printed. in this case, 3 would be printed. assume the availability of a variable, stdin, that references a scanner object associated with standard input. that is, stdin = new scanner(system.in); is given.

The total cost of textbooks for the term was collected from 36 students. create a histogram for this data. $140 $160 $160 $165 $180 $220 $235 $240 $250 $260 $280 $285 $285 $285 $290 $300 $300 $305 $310 $310 $315 $315 $320 $320 $330 $340 $345 $350 $355 $360 $360 $380 $395 $420 $460 $460