We have been playing with strings and doing some basic operations on string for the last two posts. Another such interesting operation with strings is finding one string in another string. There are a number of things to be checked while searching for a string as a substring of second one. We shall be explaining these steps and other details in the proceeding lines.
Posts Tagged ‘algorithms’
We saw how to match the two given strings last time and determine whether they first of them is less than, greater than or equal to the second string. We developed a simple string matching algorithm for that purpose. Similarly we also want to perform a number of other operations on our strings and need to find certain patterns and keys in them. Today we shall develop a simple character finding algorithm in a given string. Let us see which things we need to find out.
Human Beings like to play with string in their daily life. We deal with all sorts of alphabets and words and often try to compare them with one another. To check whether we have two given set of characters equal or not, we make use of string matching algorithms. To match the two given strings, we use then to look for equality in both the strings for the desired results. A simple string matching algorithm is to iterate over each alphabet and match correspondingly. Let us see in detail how we do that.
Deviating a little from our series of discussion on Sorting Algorithms, this time and maybe the next one too, we would be plunging into certain other core concepts considered vital and important to good programming. Last time, we carried out the Selection Sort using the recursive technique. As recursion is a tricky and fundamental topic and a very powerful tool as well, we would be having some more discussion on recursion now.
Linear search, as described last time is ineffective for method for finding piece of information, the key from a large list. If you have a database of one hundred thousand people living in Los Angeles, you would surely have a headache if you were to look at each and every element of that database to look for your key. In such situations, Binary Search comes into play. Binary search is a very efficient searching algorithm especially for large amount of data. For binary search to perform, data in the list has to be sorted beforehand.