How to Design Programs phần 10 potx

... accumulator ) ]))) (rem! a-hand0 ) )) The questions to ask now are what the accumulator represents and what its first value is. The best way to understand the nature of accumulators is to study ... accumulator empty) Now the pieces of the design puzzle fall into place. The complete definition of the function is in figure 123. The accumulator parameter is renamed to predeces...

Ngày tải lên: 12/08/2014, 19:20

... that show the reader how to analyze a problem statement; how to formulate concise goals; how to make up examples; how to develop an outline of the solution, based on the analysis; how to finish ... marker refers to teacher hints, which suggest strategies on how to present a section, on how to approach an exercise, or on how to supplement some material. T...

Ngày tải lên: 12/08/2014, 19:20

... need the two coordinates to compute the distance. Put differently, we know how to combine two numbers into a posn structure using make-posn and we don't know how to extract these numbers ... for example, how to draw and erase a circle. Here we learn to translate a circle, that is, to move its representation along some line. In sections 7.4, 10. 3, and 21.4 we l...

Ngày tải lên: 12/08/2014, 19:20

... inventory management: the cost of an inventory. In addition to a list of the available toys, a store owner should also maintain a list of the cost of each item. The cost list permits the owner to ... not draw-polygon . To get from the more general function to what we want, we need to figure out some way to connect the last dot to the first one. There are several ways to acc...

Ngày tải lên: 12/08/2014, 19:20

... 16.2.3. Show how to model a directory with two more attributes: a size and a systems attribute. The former measures how much space the directory itself (as opposed to its files and subdirectories) ... binary search trees to store and to retrieve information. To be concrete, we discuss binary trees that manage information about people. In this context, a binary tree is similar...

Ngày tải lên: 12/08/2014, 19:20

... tree (ftn) (see section 14.1) and produces a list that explains how to get to a blue-eyed ancestor. If there is no blue-eyed ancestor, the function produces false. TEAMFLY ... 8 10) , given its contract. A quick check shows that < makes sense because it belongs to the class (number number -> boolean) and (list 3 8 10) makes sense because it belong...

Ngày tải lên: 12/08/2014, 19:20

... estimate is to the actual area. Let us agree that R stands for the number of rectangles that we wish to consider. To determine how large these rectangles are, we need to figure out how large ... Make R a top-level constant: ;; R : number of rectangles to approximate integral (define R ) Test integrate on sin and increase R gradually from 10 to 100 00 . What h...

Ngày tải lên: 12/08/2014, 19:20

... are 100 0 for F and 1 for G . One way to compare the two claims is to tabulate the abstract running time: N 1 10 50 100 500 100 0 F (100 0 · N) 100 0 100 00 50000 100 000 500000 100 0000 ... vectors. A vector is a well-defined mathematical class of data with specific basic operations. For our purposes, it suffices to know how to construct them, how to extrac...

Ngày tải lên: 12/08/2014, 19:20

... master-check uses. Let us now study how the design recipe applies to the development of the program. The first step is to define the state variables and to specify the purpose of each variable. ... small numbers and the result is too small to fit into our class of inex structures: (inex* (create-inex 1 -1 10) (create-inex 1 -1 99)) = (create-inex 1 -1 109 ) which ca...

Ngày tải lên: 12/08/2014, 19:20

... individual traffic light. That is, in addition to switching from the current color to the next, an operator should be able to set a traffic light to red. The function for doing so already exists: ... effect: to change current-color from 'green to 'yellow, ;; 'yellow to 'red, and 'red to 'green (define (next) ) ;; next-color : TL-color -&...

Ngày tải lên: 12/08/2014, 19:20