Red and Black
Time limit:2000/1000 MS (java/others) Memory limit:65536/32768 K (java/others)
Total submission (s): 11531 Accepted Submission (s): 7177
Problem 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)
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
Source
Asia 2004, Ehime (Japan), Japan Domestic
#include <stdio.h> #include <string.h>int n,m,cnt;char map[30][30];int to[4][2] = {{1,0},{0,1},{-1,0},{0,- 1}};void DFS (int i,int j) {int k,x,y; cnt++; MAP[I][J] = ' # '; for (k = 0; k<4; k++) { x = i + to[k][0]; y = j + to[k][1]; if (x<n && y<m && x>=0 && y>=0 && map[x][y] = = '. ') Control x, y do not let it cross the dfs (x, y); }} int main () { int i,j,fi,fj; while (scanf ("%d%d%", &m,&n))//horizontal is n, longitudinal is m { if (m==0&&n==0) break; for (i = 0; i<n; i++) { for (j = 0; j<m; j + +) { scanf ("%c", &map[i][j]); if (map[i][j] = = ' @ ')//Find the location of the first person { fi = i; FJ = j; } } GetChar (); } CNT = 0; DFS (FI,FJ); printf ("%d\n", CNT); } return 0;}
HDU 1312 Red and Black "Deep Search"