遗传算法实现计算f(x 1,x 2 )= 21.5 +x 1 ·sin(4πx 1 ) +x 2 ·sin(20πx 2 )的最大值-calculate the maximum value of f(x 1,x 2 )= 21.5+x 1 ·sin(4πx 1 )+x 2 ·sin(20πx 2 ) by Genetic Algorithm