粒子群求解无约束优化问题，包括基本粒子群算法，改进的粒子群算法，还有基于自然选择的粒子群算法和模拟退火的粒子群算法-Swarm for unconstrained optimization problems, including particle swarm algorithm, the improved particle swarm optimization, as well as natural selection based on PSO and simulated annealing p