是的,,我的目的是要得到字符串"x5*x1^4*x2^2*x3^2*x4^4+x5*x1^4*x2*x3^2*x4^2+x5*x1^2*x2^2*x3*x4^4+x2*x3*x5^2*x1^2*x4+x2*x3*x5^2*x1*x4^2",然后对其进行排序或者拿掉其中一部分,但串"x5*x1^4*x2^2*x3^2*x4^4+x5*x1^4*x2*x3^2*x4^2+x5*x1^2*x2^2*x3*x4^4+x2*x3*x5^2*x1^2*x4+x2*x3*x5^2*x1*x4^2"就得不到.谢谢!