Realization of operations: algorithms

Usually, we realize an operation when we need to solve a specific problem.

Example: given a person name, find the corresponding telephone number in a telephone registry.

To delegate to a computer the solution of a problem, it is necessary to find an algorithm that solves the problem.

Algorithm: procedure through which we obtain the solution of a problem. In other words, a sequence of instructions that, when executed in sequence, allow one to calculate the solution of the problem starting from the information provided as input.

An algorithm is characterized by:

• non ambiguity: the instructions must be interpretable in a unique way by whom is executing them
• executability: it must be possible to execute each instruction (in a finite amount of time) given the available resources
• finiteness: the execution of the algorithm must terminate in a finite amount of time for each possible set of input data

Example of an algorithm: scan the person names, one after the other as they appear in the registry, until you have found the requested one; return the associated telephone number.

Are there other algorithms to solve the same problem? Yes!

Once we have found/developed an algorithm, we have to code it in the selected programming language.