回溯法是一种选优搜索法，按选优条件向前搜索，以达到目标但当探索到某一步时，发现原先选择并不优或达不到目标，就退回一步重新选择。这种走不通就退回再走的技术为回溯法，而满足回溯条件的某个状态的点称为“回溯点”。回溯算法是所有搜索算法中最为基本的一种算法，其采用了一种“走不通就掉头”思想作为其控制结构 -Backtracking is a search optimization method, based on forward selection search terms in order to achieve a certain goal but to explore further, it was found that the original selection is not gifted or can not achieve this objective, we step back to re-select. This leads back to go on the back of technology, law, and back to meet the conditions of the status of a point referred to as " backward point."　Backtracking algorithm for all search algorithms are the most basic of an algorithm, which uses a " dead end on the U-turn"　as part of its control structure thought