[ bīng lái jiàng dí，shuǐ lái tǔ yàn ]

敌：对抗；堰：拦河坝。敌人来了派将军抵挡，大水来了用土去掩盖。比喻针锋相对，根据具体情况，采取灵活的对付办法。

元·无名氏《云台门》第一折：“兵来将敌，水来土堰，兄弟也，你领兵就随着我来，不可延迟也。”

to adopt measures appropriate to the actual situation; counter soldiers with arms, water with an earth weir (idiom); different situations call for different action