算法（Algorithm）是一系列解决问题的清晰指令，也就是说，能够对一定规范的输入，在有限时间内获得所要求的输出。如果一个算法有缺陷，或不适合于某个问题，执行这个算法将不会解决这个问题。不同的算法可能用不同的时间、空间或效率来完成同样的任务。一个算法的优劣可以用空间复杂度与时间复杂度来衡量。-Algorithm (Algorithm) is a set of clear instructions to solve the problem, that is, able to a certain standard input, in a limited period of time to obtain the required output. If an algorithm is defective, or not suitable for a particular problem, the implementation of this algorithm will not solve the problem. Different algorithms may use a different time, space or efficiency to accomplish the same task. Pros and cons of an algorithm can use space complexity and time complexity of the evaluation.