使用三种不同的粒子群算法，分别求解函数的极值，三种算法循序渐进，但每一种都有部分改进，新手上路，可以很好的感受到粒子群算法的变化特性(Three different particle swarm optimization algorithms are used to solve the extremum of the function, three algorithms are progressive, but each one has some improvements, beginners on the road, you can feel the changing characteristics of particle swarm optimization algorithm.)