来自孔贵芹的问题
java排列组合的算法譬如我有（A,B,C,D）,我想输出的结果是{A,B,C,D}{AB},{AC},{AD},{BC},{BD},{CD}{ABC},{ABD},{ACD},{BCD}{ABCD}
java排列组合的算法譬如我有（A,B,C,D）,我想输出的结果是
{A,B,C,D}
{AB},{AC},{AD},{BC},{BD},{CD}
{ABC},{ABD},{ACD},{BCD}
{ABCD}
