E-Sources Informatics

From time to time in our activities,we employ algorithms to solve program,for example,to look up someone’s  telephone number in a telephone directory we need to employe an algorithm.Task such as this are usually mechanism needed to effectively conduct the search. It therefore come as some what of surprise to us when developing computer algorithms that solution must be specified with such logical precision and in such detail.After studying even a small sample of computer problem it soon become obivious that consicious depth of understanding needed to desing effective computer algoritms is far greather than we are likely to encounter in almost any other problem-solving situation.

                Let us reflect for a moment on the telephone directory loo-up problem .A telephone directory quite often hundreds of thousands of names and telephone number yet we have little trouble finding the desired telephone number we are seeking.we might therefore ask why do we have so little difficulty with problem of seemingly greet size?The answer is simple.we quite naturaly take anvantage of the order in directory to quickly eliminate large sections of the list and home in on the desired name and number.We would never comtemplate looking up the telephone number of J.R Nash by staring at page  1 and examining each nema in turn until  we finaly come to Nas’h name and telephone number.nor are we likely to comtemplete looking up the name person whose Number 2987533.To conduct such a search,there is no way in which we can take advantage of the order in the directory and so we are  faced with the prospect of doing a number-by-number search string at apge 1.if,on the other hand,we had a list  of telephone number and names ordered by telephone number rather than name ,the task would be straight forward.what these example serve to emphasize is the important influence of the data organization on the performace of algorithms.Only when a data structure is symbiotically linked with and algorithm can we expect high performace.Before considering these and other aspects of algorithm desing we need to address the topic of problem solving in some detail