Use Of Basic Data Structures Pdf
Data-Structures-3rd-Edition-400x500.jpg' alt='Use Of Basic Data Structures Pdf' title='Use Of Basic Data Structures Pdf' />Offered as an introduction to the field of data structures and algorithms, Open Data Structures covers the implementation and analysis of data structures for. See how to loop code and conditionally execute code in LabVIEW using For Loops, While Loops, and Case structures. Paper 26929 DATA Step vs. PROC SQL Whats a neophyte to do Craig Dickstein, Tamarack Professional Services, Jackman, ME Ray Pass, Ray Pass Consulting. I am using this class successfully to generate PDFs. I have a problem. I am pulling data from a database adding customer information and parts information together. Persistent data structure Wikipedia. In computing, a persistent data structure is a data structure that always preserves the previous version of itself when it is modified. Such data structures are effectively immutable, as their operations do not visibly update the structure in place, but instead always yield a new updated structure. A data structure is partially persistent if all versions can be accessed but only the newest version can be modified. Paper 2072008 Practical Methods for Creating CDISC SDTM Domain Data Sets from Existing Data Robert W. Graebner, Quintiles, Inc., Overland Park, KS. You will learn how to take a problem and state it precisely using an algorithm so that it can be solved with a computer. The data structure is fully persistent if every version can be both accessed and modified. If there is also a meld or merge operation that can create a new version from two previous versions, the data structure is called confluently persistent. Structures that are not persistent are called ephemeral. These types of data structures are particularly common in logical and functional programming, and in a purely functional program all data is immutable, so all data structures are automatically fully persistent. Persistent data structures can also be created using in place updating of data and these may, in general, use less time or storage space than their purely functional counterparts. L02_notes/00.jpg' alt='Use Of Basic Data Structures Pdf' title='Use Of Basic Data Structures Pdf' />Purely functional data structures are persistent data structures that completely avoid the use of mutable state, but can often still achieve attractive amortized time complexity bounds. While persistence can be achieved by simple copying, this is inefficient in CPU and RAM usage, because most operations make only small changes to a data structure. A better method is to exploit the similarity between the new and old versions to share structure between them, such as using the same subtree in a number of tree structures. However, because it rapidly becomes infeasible to determine how many previous versions share which parts of the structure, and because it is often desirable to discard old versions, this necessitates an environment with garbage collection. However, it is not so infeasible that a sophisticated project, such as the ZFScopy on write file system, is unable to achieve this by tracking storage allocation directly. Partially persistenteditIn the partial persistence model, we may query any previous version of the data structure, but we may only update the latest version. This implies a linear ordering among the versions. Three methods on balanced binary search tree Fat nodeeditFat node method is to record all changes made to node fields in the nodes themselves, without erasing old values of the fields. This requires that we allow nodes to become arbitrarily fat. In other words, each fat node contains the same information and pointer fields as an ephemeral node, along with space for an arbitrary number of extra field values. Each extra field value has an associated field name and a version stamp which indicates the version in which the named field was changed to have the specified value. Besides, each fat node has its own version stamp, indicating the version in which the node was created. The only purpose of nodes having version stamps is to make sure that each node only contains one value per field name per version. In order to navigate through the structure, each original field value in a node has a version stamp of zero. Complexity of fat nodeeditWith using fat node method, it requires O1 space for every modification just store the new data. Each modification takes O1 additional time to store the modification at the end of the modification history. This is an amortized time bound, assuming we store the modification history in a growable array. For access time, we must find the right version at each node as we traverse the structure. If we made m modifications, then each access operation has Olog m slowdown resulting from the cost of finding the nearest modification in the array. Path copyingeditPath copy is to make a copy of all nodes on the path which contains the node we are about to insert or delete. Then we must cascade the change back through the data structure all nodes that pointed to the old node must be modified to point to the new node instead. These modifications cause more cascading changes, and so on, until we reach to the root. We maintain an array of roots indexed by timestamp. The data structure pointed to by time ts root is exactly time ts data structure. Complexity of path copyingeditWith m modifications, this costs Olog m additive lookup time. Modification time and space are bounded by the size of the structure, since a single modification may cause the entire structure to be copied. That is Om for one update, and thus On preprocessing time. A combinationeditSleator, Tarjan et al. O1 access slowdown and O1 modification space and time. In each node, we store one modification box. This box can hold one modification to the nodeeither a modification to one of the pointers, or to the nodes key, or to some other piece of node specific dataand a timestamp for when that modification was applied. Initially, every nodes modification box is empty. Whenever we access a node, we check the modification box, and compare its timestamp against the access time. The access time specifies the version of the data structure that we care about. If the modification box is empty, or the access time is before the modification time, then we ignore the modification box and just deal with the normal part of the node. On the other hand, if the access time is after the modification time, then we use the value in the modification box, overriding that value in the node. Say the modification box has a new left pointer. Then well use it instead of the normal left pointer, but well still use the normal right pointer. Modifying a node works like this. We assume that each modification touches one pointer or similar field. If the nodes modification box is empty, then we fill it with the modification. Otherwise, the modification box is full. We make a copy of the node, but using only the latest values. That is, we overwrite one of the nodes fields with the value that was stored in the modification box. Then we perform the modification directly on the new node, without using the modification box. We overwrite one of the new nodes fields, and its modification box stays empty. Finally, we cascade this change to the nodes parent, just like path copying. This may involve filling the parents modification box, or making a copy of the parent recursively. If the node has no parentits the rootwe add the new root to a sorted array of roots. With this algorithm, given any time t, at most one modification box exists in the data structure with time t. Thus, a modification at time t splits the tree into three parts one part contains the data from before time t, one part contains the data from after time t, and one part was unaffected by the modification. Complexity of the combinationeditTime and space for modifications require amortized analysis. A modification takes O1 amortized space, and O1 amortized time. To see why, use a potential function, where T is the number of full live nodes in T. The live nodes of T are just the nodes that are reachable from the current root at the current time that is, after the last modification. The full live nodes are the live nodes whose modification boxes are full. Each modification involves some number of copies, say k, followed by 1 change to a modification box. Well, not quiteyou could add a new rootbut that doesnt change the argument. Consider each of the k copies. What is a data structure Lets get some ground rule together. This term, data structure, might seem a little abstract, a little non specific. And, usually, its program is were going to nail that definition down. Well, what does that mean exactlyBut for our purposes, abstract andnon specific is good, its flexible, its useful. Because a data structure is exactly what it sounds like. Its just some arrangement of data that weve built. Not one lone integer variable over here and a string over here and afull one down here but weve gathered some data together into an orderly arrangement. Why Because its useful, because it makes our lives easier to do this. The same way that if youre working in bills and taxes, youre likely to gatheryour paperwork together into stacks or folders, andthen perhaps your folders into a filing cabinet. Because its easy to manage when you keep related information together. That you would always write a recipewith the ingredients and the description togetherbecause if the exact same information issplit up and disconnected its kind of pointless. Youll end up with, single piece of paper that says four ounces of flour. So we need data structures in our programs because we thinkthis way as human beings, its easy to forget this sometimes. We start learning about data structures and were immediatelysurrounded with terms like associative arrays and binary search trees. And they sound completely detached from anything wed ever do as a human being. But theyre not, we naturally think in data structures. Okay, we dont use that term, but we think in collections of information. A recipe is an actual data structure, as is a shopping list. A telephone directory, a dictionary, a thesaurus, anencyclopedia, a flight schedule, these are not haphazard. They have a structure, they have a format. So imagine a bank statement, we can hold that single conceptin our head and we know its a collection of information. Microsoft Digital Media Pro Keyboard Program Keys. Its an arrangement of data, its not random. Its an intentional list of transactions withan order to it and each transaction itselfis in intentional arrangement of data, information, thedate, the amount, who its from or to. And these have nothing to do with computers, wedidnt need a computer to have a bank statement ora telephone directory or a shopping list, they all existedlong before computers were a glint in Charles Babbages eye. Now if youre an object oriented programmer, you may bethinking, Well isnt this what we do with classes and objects I mean, we define these real world objects in a programbecause we think like, or at least were supposed to. And yes, absolutely. And well kind of get into that later, but objectsare a type of data structure, just not the only type. I purposefully use simple, real world examples, because this term datastructure does not and should not imply a level of complexity. Sure, we can have huge complex data structures, butwe need a lot of small straight forward ones too. So, our working definition in this course is that. A data structure is just an intentional arrangement of data, thats it. Its a proudly non specific definition and it covers a whole range of possibilities. There is, however, one line I am going to draw. That our focus in this course is on data structures created and held. In memory, in a running computer program. Yes, at some point you may want to take some or all of that data and persist it. Save it out to a file on disk, or send over the network tocloud storage or to a database, but that is not what were talking about here. Sure, when youre working with databases, SQL Server, Oracle, My. SQL. We have tables, we have rows and columns, and that does meet that definition ofan intentional arrangement of data, but Itrust you understand where Im drawing the distinction. Once that data leaves our program to go to a diskdrive or a separate server, that is a different set of issues. So our attention here is on theintentional arrangement of data held in memory. Inside a running application. So with that simple and non specific definition in place, letstake a look at some simple and non specific data structures.