Top 20 String Algorithm Questions from Coding Interviews In this article, we are going to see top 20 String based coding interview question and their solution to help programmers better prepare for interviews. The string is one of the most important data structure and available in almost every programming language e. Though there implement differ but the essence remains same e. The string is also available on weekly typed language e.
Others use the " " character. As long as it's not in the string you are looking for, anything goes. And remember that you need three delimiters. Sometimes you want to search for a pattern and add some characters, like parenthesis, around or near the pattern you found.
It is easy to do this if you are looking for a particular string: How can you put the string you found in the replacement string if you don't know what it is? You could also double a pattern, e. Sed will match the first string, and make it as greedy as possible. I'll cover that later.
If you don't want it to be so greedy i. So if the input was "abc " the output would be unchanged well, except for a space before the letters.
A better way to duplicate the number is to make sure it matches a number: Extended Regular Expressions Let me add a quick comment here because there is another way to write the above script. Therefore you must explicitly enable this extension with a command line option.
GNU sed turns this feature on if you use the "-r" command line option. To review, the escaped parentheses that is, parentheses with backslashes before them remember a substring of the characters matched by the regular expression. You can use this to exclude part of the characters matched by the regular expression.
Sed has up to nine remembered patterns. If you wanted to keep the first word of a line, and delete the rest of the line, mark the important part with the parenthesis: Regular expressions are greedy, and try to match as much as possible.
Since the first one grabs all of the contiguous lower case letters, the second matches anything else.
If you want to switch two words around, you can remember two patterns and change the order around: This is used to make sure two words are found.
However, this will do nothing if a single word is found, or any lines with no letters. It can be in the pattern you are searching for in the left hand side.
If you want to eliminate duplicated words, you can try: The numeric value can have up to nine values: You might have noticed I used a 'p' at the end of the previous substitute command.
I also added the '-n' option. Let me first cover the 'p' and other pattern flags. These flags can specify what happens when a match is found.
Let me describe them. Sed, by default, is the same way.
If you tell it to change a word, it will only change the first occurrence of the word on a line.I'd like to reverse the order of lines in a text file (or stdin), preserving the contents of each line.
So, i.e., starting with: foo bar baz I'd like to end up with baz bar foo Is there a sta. C Program Print a list of numbers in reverse order by Dinesh Thakur Category: Array In this program, an array num of type int is used to store the given integer numbers and variable nelem to .
this is my source code for printing each word in string backwards. but this code is just printing the 1st word backward and not the entire string. after printing 1st word backward it generates a pattern of 1st and 2nd words printed backwards.
If while is used instead of if then it generates an infinite loop. Task. Encode a string using an MD5 algorithm. The algorithm can be found on Wikipedia. Optionally, validate your implementation by running all of the test values in IETF RFC () for MD5.
Additionally, RFC provides more precise information on the algorithm than the Wikipedia article. The first declaration of month is explicit about returning a Month and about not modifying the state of the Date object.
The second version leaves the reader guessing and opens more possibilities for uncaught bugs. Example; bad.
This loop is a restricted form of std::find. Table of Content. C Program to print table of n and square of n using pow() C Program to find Factorial of Number without using function; C Program to Access Address of Variable using Pointer.