All entries for Monday 31 July 2006
July 31, 2006
There is an interesting puzzle of six frogs, three of them are lime (L) and the other three are red ®, which goes as the following. Frogs are sitting in the middle of a pond on a sequence of seven stones in following order.
Here _ represents a free stone. Frogs can jump to a free stone only if they respect following rules:
1. L frogs can only move towards the right side.
2. R frogs can only move towards the left side.
3. A frog can jump over maximum one frog, i.e., frogs can not jump two places in one jump.
The problem is to find number of moves, in which all the Lime frogs are in right hand side and all the red frogs are in left hand side. That is we wish to reach the configuration RRR_LLL, starting from LLL_RRR.
Some example set of moves are as following:
LLL_RRR –> LLLR_RR
LLL_RRR –> LL_LRRR
LRLR_LR –> LR_RLLR
End of the puzzle.
Solution is here.