摘要： http://blog.csdn.net/whinah/article/details/6419680从理论上讲，只要允许使用栈，所有的递归程序都可以转化成迭代。但是并非所有递归都必须用栈，不用堆栈也可以转化成迭代的，大致有两类尾递归：可以通过简单的变换，让递归作为最后一条语句，并且仅此一个递归调用。// recursiveint fac1(int n) { if (n <= 0) return 1; return n * fac1(n-1);}// iterativeint fac2(int n) { int i = 0, y = 1; for (; i <= n; ... 阅读全文

摘要： A child is running up a staircase with N steps, and can hop either 1 step,2steps,3 steps at a time. Count how many possible ways the child can run up the stairs. class Upstaircase { static void Main(string[] args) { /* Enter your code here. Read input from STDIN. Print ou... 阅读全文