可⾏性剪枝就是把能够想到的不可能出现的情况给它剪掉 。该⽅法判断继续搜索能否得出答案,如果不能直接回溯。【例1】Sum It Up (POJ 1564)Description Given a specified total t and a list of n integers, find all distinct sums using numbers from the list that add up to t. For example, if...