不知道partition是不是指这个意思1.单元素只有一种划分{a}==>{{a}}2.两元素两种{a,b}==>{{a,b}}{{a}{b}}3.三元素五种3=3+0.......1=1+2........3=1+1+1......1{a,b,c,d,e}==>{ {a}, {b}, {c} } { {a}, {b, c} } { {b}, {a, c} } { {c}, {a, b} } { {a, b, c} } 4.四元素15种==>4=4+0......1=3+1.......4=2+2.......3=1+1+2.....6=1+1+1+1...15.五元素52种==>5=5+0......1=4+1.......5=3+2.......10=1+1+3.....10=1+2+2.....15=1+1+1+2....10=1+1+1+1+1..1