What is the word that describes someone who displays the ability to think of alternative ways of dealing with a situation, especially a situation that calls for it and then acts upon it? In my native language, it is a relatively common word. As I thought of it, the idiom think on your feet, and the word nimble sprang to mind. It is the closest expressions I could think of, although it is similar, it does not contain the exact meaning of that word.
Basically it's an adjective that describes someone who's able to quickly think of alternatives in a situation, especially in a situation that calls for it. He is able to accommodate to new situations as opposed to someone who, if faced with a similar situation, will become stuck, not knowing what to do and unable to think of any alternatives.
For example, If someone who's shopping for ingredients for the desired dinner he's going to prepare for his party guests discovered that one of the ingredients for a dish he's going to prepare is not sold in any of his local grocery stores, he buys another similar ingredient as a substitute. He is (that word), because he has the ability to think of alternative ways in dealing with the situation where as someone who is not (that word) is rather dull and when faced with such situations, will propably decides not to prepare that dish and may also get frustrated/upset over the matter.