Introduction - If you have any usage issues, please Google them yourself
The "Jiaotusanku" means many rabbits can hide the cave to protect themselves, now let s hypothesis that there have a fox, a rabbit and 10 holes (hole numbers 0 to 9) for rabbits.
Fox so find rabbit, First hole: fox standing No. 0, step 1 (step 1), the next hole is on the 1st hole, standing on the 1st hole, step+1 (this 2) time step, the next hole is on the 3rd hole, standing on the 3rd hole, step+1 (step 3), the next hole is on the 6th hole ... etc.
Q: fox can catch the rabbit, please write code to prove.