CF327D.Block Tower

普及/提高-

通过率:0%

AC君温馨提醒

该题目为【codeforces】题库的题目,您提交的代码将被提交至codeforces进行远程评测,并由ACGO抓取测评结果后进行展示。由于远程测评的测评机由其他平台提供,我们无法保证该服务的稳定性,若提交后无反应,请等待一段时间后再进行重试。

题目描述

After too much playing on paper, Iahub has switched to computer games. The game he plays is called "Block Towers". It is played in a rectangular grid with nn rows and mm columns (it contains n×mn×m cells). The goal of the game is to build your own city. Some cells in the grid are big holes, where Iahub can't build any building. The rest of cells are empty. In some empty cell Iahub can build exactly one tower of two following types:

  1. Blue towers. Each has population limit equal to 100100 .
  2. Red towers. Each has population limit equal to 200200 . However, it can be built in some cell only if in that moment at least one of the neighbouring cells has a Blue Tower. Two cells are neighbours is they share a side.

Iahub is also allowed to destroy a building from any cell. He can do this operation as much as he wants. After destroying a building, the other buildings are not influenced, and the destroyed cell becomes empty (so Iahub can build a tower in this cell if needed, see the second example for such a case).

Iahub can convince as many population as he wants to come into his city. So he needs to configure his city to allow maximum population possible. Therefore he should find a sequence of operations that builds the city in an optimal way, so that total population limit is as large as possible.

He says he's the best at this game, but he doesn't have the optimal solution. Write a program that calculates the optimal one, to show him that he's not as good as he thinks.

输入格式

The first line of the input contains two integers nn and mm ( 1<=n,m<=5001<=n,m<=500 ). Each of the next nn lines contains mm characters, describing the grid. The jj -th character in the ii -th line is '.' if you're allowed to build at the cell with coordinates (i,j)(i,j) a tower (empty cell) or '#' if there is a big hole there.

输出格式

Print an integer kk in the first line (0<=k<=106)(0<=k<=10^{6}) — the number of operations Iahub should perform to obtain optimal result.

Each of the following kk lines must contain a single operation in the following format:

  1. «B x y» (1<=x<=n,1<=y<=m)(1<=x<=n,1<=y<=m) — building a blue tower at the cell (x,y)(x,y) ;
  2. «R x y» (1<=x<=n,1<=y<=m)(1<=x<=n,1<=y<=m) — building a red tower at the cell (x,y)(x,y) ;
  3. «D x y» (1<=x<=n,1<=y<=m)(1<=x<=n,1<=y<=m) — destroying a tower at the cell (x,y)(x,y) .

If there are multiple solutions you can output any of them. Note, that you shouldn't minimize the number of operations.

输入输出样例

  • 输入#1

    2 3
    ..#
    .#.
    

    输出#1

    4
    B 1 1
    R 1 2
    R 2 1
    B 2 3
    
  • 输入#2

    1 3
    ...
    

    输出#2

    5
    B 1 1
    B 1 2
    R 1 3
    D 1 2
    R 1 2
    
首页