A program stores total order numbers arrived at different time. For example, at 1.15 pm the program got 15 order, at 1.30 pm, the program got 20 order and so on.Now we need to design the data structure so that we can query the total orders we got in a time range efficiently. For this example, we can query as How many orders we have got between 1 and 2 pm? Ans will be 15+ 20 = 35