In solving a problem of this sort, the grant thing is to be able to reason backward.

在解决这类问题时，先前假定的观点必须能够向前回溯成立。

youdao

In solving a problem of this sort, the grant thing is to be able to reason backward.

在解决这类问题时，先前假定的观点必须能够向前回溯成立。

youdao