说明：  A new metaheuristic optimization algorithm, called Cuckoo Search (CS), is fully implemented, and the vectorized version is given here. This code demonstrates how CS works for unconstrained optimization, which can easily be extended to solve various global optimization problems efficiently. Three versions are provided: Cuckoo_search.m is for a given tolerance. Cuckoo_search_new.m is for a fixed number of iterations. Cuckoo_search_spring.m is constrained optimization for designing a spring.