Score : 700 points
There are N cats. We number them from 1 through N.
Each of the cats wears a hat. Cat i says: "there are exactly a_i different colors among the N - 1 hats worn by the cats except me."
Determine whether there exists a sequence of colors of the hats that is consistent with the remarks of the cats.
Input is given from Standard Input in the following format:
N a_1 a_2 ... a_N
Print Yes
if there exists a sequence of colors of the hats that is consistent with the remarks of the cats; print No
otherwise.
3 1 2 2
Yes
For example, if cat 1, 2 and 3 wears red, blue and blue hats, respectively, it is consistent with the remarks of the cats.
3 1 1 2
No
From the remark of cat 1, we can see that cat 2 and 3 wear hats of the same color. Also, from the remark of cat 2, we can see that cat 1 and 3 wear hats of the same color. Therefore, cat 1 and 2 wear hats of the same color, which contradicts the remark of cat 3.
5 4 3 4 3 4
No
3 2 2 2
Yes
4 2 2 2 2
Yes
5 3 3 3 3 3
No