单点时限: 2.0 sec
内存限制: 256 MB
The farm has many hills upon which Farmer John would like to place guards to ensure the safety of his valuable milk-cows.
He wonders how many guards he will need if he wishes to put one on top of each hill. He has a map supplied as a matrix of integers; the matrix has $N$ ($1 < N \le 700$) rows and $M$ ($1 < M \le 700$) columns. Each member of the matrix is an altitude $H_{ij}$ ($0 \le H_{ij} \le 10,000$).
Help him determine the number of hilltops on the map.
A hilltop is one or more adjacent matrix elements of the same value surrounded xclusively by either the edge of the map or elements with a lower (smaller) altitude. Two different elements are adjacent if the magnitude of difference in their $X$ coordinates is no greater than $1$ and the magnitude of differences in their $Y$ coordinates is also no greater than $1$.
8 7 4 3 2 2 1 0 1 3 3 3 2 1 0 1 2 2 2 2 1 0 0 2 1 1 1 1 0 0 1 1 0 0 0 1 0 0 0 0 1 1 1 0 0 1 2 2 1 1 0 0 1 1 1 2 1 0
3
OUTPUT DETAILS:
There are three peaks: The one with height 4 on the left top, one of the points with height 2 at the bottom part, and one of the points with height 1 on the right top corner.