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