Canal-U

1.4. What is an algorithm?

We have seen that a genomic textcan be indeed a very long sequence of characters. And to interpret this sequence of characters, we will need to use computers. Using computers means writing program. Writing program means designing first algorithm. So, let's see what an algorithm is. An algorithm is a series of operationsto be executed by a computer, but maybe also executed by ahuman, for solving a problem.  In the first algorithm we will study in this session and next one, the problem will be to count the number of different of the four different nucleotides which appeared in the sequence. It's a sequence of operations. You may say that in everyday life,we have an example of algorithm with the recipe. But no,it's not totally correct. A recipe, the description of arecipe is not formal, explicit, precise enough to be an algorithm.  There are too many approximations,too many shortcuts of language. For example, you have to put eggs in the bowl but it doesn't say that you have tobreak the eggs, first.
You don't have to throw the shells on the floor, for example.