说明：  给出从m个数中取n个数的所有组合,解决了组合数学中的一个难题,例如从6中取4个具体情况怎样,本程序给出(1,2,3,4)(1,2,3,5)....等等每一种取法.
(Given from the m number of n number of check all the combinations, the combination of mathematics to solve a problem, for example, from 6 in check how four specific circumstances, this procedure gives (1,2,3,4) (1 , 2,3,5 ).... so取法each.)