来源http://poj.org/problem?id=2248 An addition chain for n is an integer sequence <a0,a1,a2,…,am><a0,a1,a2,…,am> with the following four properties: a0 = 1 am = n a0< a1< a2<…< am-1< a m For each k ( 1≤k≤m1≤k≤m) there exist two (not neccessarily different) integers i a...