NC222455. [USACOJan2020P]CavePaintings
描述
输入描述
The first line contains two space-separated integers [Math Processing Error] and [Math Processing Error].
The next [Math Processing Error] lines of input each contain [Math Processing Error] characters. Each character is either '.' or '#', representing an empty square and a square filled with rock, respectively. The first and last row and first and last column only contain '#'.
输出描述
A single integer: the number of paintings satisfying the constraint modulo [Math Processing Error].
示例1
输入:
4 9 ######### #...#...# #.#...#.# #########
输出:
9
说明:
If a square in the second row is filled with water, then all empty squares must be filled with water. Otherwise, assume that no such squares are filled with water. Then Bessie can choose to fill any subset of the three horizontally contiguous regions of empty squares in the third row. Thus, the number of paintings is equal to [Math Processing Error]