NAND is a logic algorithm, which often exists in the form of "NAND gate" in computers. Expressed as NAND. The combination of "right and wrong" and "negation" is equivalent.
It is not a logical algorithm, and it often exists in the form of "nor gate" in computers. "NOR" and disjunctive negation are equivalent. It means: not really.
An algorithm can be understood as a complete problem-solving step consisting of a basic operation and a specified operation sequence, or as a limited and accurate calculation sequence designed according to requirements. Such steps and sequences can solve a class of problems.
The general algorithm has three basic logical structures: sequence structure, selection structure and circulation structure. The common features of these three basic structures are:
1, there is only one entrance and exit.
2. Every part of the structure has a chance to be executed, that is to say, every box should have a path from the entrance to the exit through it, and no path from the entrance to the exit passes through it, which is an unqualified algorithm structure.
3. There is no infinite loop in the structure, that is, infinite loop, which is not allowed in the flow chart.