W=(complex *)malloc(sizeof(complex) *

W=(complex *)malloc(sizeof(complex) *
W=(complex *)malloc(sizeof(complex) *

W=(complex *)malloc(sizeof(complex) *
意思是申请一块内存,其大小是M个complex长度的总和.然后把这块内存的首地址强转成complex *指针变量类型,赋给W.