Red and Black Deep Search

 B-Red and Black crawling in process ... crawling failedTime limit:MS Memory Limit:30000KB 64bit IO Format: %I64D &%i64u SubmitStatus

Description

There is a rectangular and covered with square tiles. Each tile is colored either red or black. A man was standing on a black tile. From a tiles, he can move to one of the four adjacent tiles. But he can ' t move on red tiles, and he can move only on black tiles.

Write a program to count the number of black tiles which he can reach by repeating the moves described above.

Input

The input consists of multiple data sets. A data set starts with a line containing the positive integers W and H; W and H is the numbers of tiles in the X-and y-directions, respectively. W and H is not more than 20.

There is H more lines in the data set, and each of the which includes W characters. Each character represents the color of a tile as follows.

'. '-a black tile
' # '-A red tile
' @ '-a man on a black tile (appears exactly once in a data set)
The end of the input is indicated by a line consisting of the zeros.

Output

For each data set, your program should output a line which contains the number of tiles he can reach from the initial tile (including itself).

Sample Input

6 9....#......#..............................#@...#.#. #.11 9.#..........#.#######. #.#.....#.. #.#.###.#.. #.#[email protected]#.#. #.#####.#.. #.......#.. #########............ 11 6..#. #.. #....#.. #.. #....#.. #.. ###.. #.. #.. #@...#.. #.. #....#.. #.. #.. 7 7..#.#....#.#. ###.###[email protected]###.###. #.#....#.#.. 0 0

Sample Output

4559613

Test instructions: It's just a matter of how many steps you can take to get where you are.

Idea: Find the place to do a deep search there are four directions, no pruning

AC Code:

#include <iostream> #include <cstdio>using namespace std;

Char map[20][20];int b[4]={0,1,-1,0};int bb[4]={1,0,0,-1};int r,c;int sx,sy;int tol;int ok (int x,int y) {  & nbsp if (x<0| | y<0| | x>=r| | y>=c| | map[x][y]== ' # ') return 0;    return 1; void Dfs (int x,int y) {    for (int i=0;i<4;i++) {        map[x][y ]= ' # ';        if (ok (X+b[i],y+bb[i])) {             tol++;            DFS (x+b[ I],y+bb[i]);       }   }}int Main () {    while ( scanf ("%d%d", &c,&r)!=eof&&r!=0&&c!=0) {        GetChar ();        for (int i=0;i<r;++i) {                 for (int j=0;j<c;j++) {                    scanf ("%c", &map[i][j]);// Remember here gets () is not possible, may enter the space                     if (map[i][j]== ' @ ') {                     sx=i;                     sy=j;                   }                }        if (i<r-1) { GetChar ();}

} tol=1;        DFS (SX,SY);    printf ("%d\n", tol); } return 0;}

This has been done before, see or find a little strange, long time do not knock on the forgotten how to do, and strengthen.

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Red and Black Deep Search