1.采用dfs：
#include <iostream>
#include <cstdio>#include <cstring>#include <string>using namespace std;char map[25][25];int count = 1;int r,c;int dx[4] = {1,-1,0,0};int dy[4] = {0,0,1,-1};bool judge(int x,int y){ if(x<0 || x>= r || y < 0 ||y>=c) return 0; return 1;}void dfs(int x,int y){ map[x][y] = '#'; int nx = 0; int ny = 0; for(int i = 0 ; i < 4; i++) { nx = x + dx[i]; ny = dy[i] + y; if(!judge(nx,ny)) continue; if(map[nx][ny] == '.') { count++; dfs(nx,ny); } }}int main(){ //freopen("test.in", "r", stdin); while(cin>>c>>r && r&&c) { count = 1; int x0,y0; for(int i = 0; i < r; i++ ) { for(int j = 0 ; j < c; j++) { cin>>map[i][j]; if(map[i][j] == ) { x0 = i; y0 = j; } } } dfs(x0,y0); cout<<count<<endl; } return 0;}
2.bfs:
#include#include using namespace std;structnode { int r; int l;};int m, n, sr, sl;int dir[2][4] = { { -1, 1, 0, 0}, { 0, 0, -1, 1}};int visited[20][20];int BFS();int main(){ int i, j; char str[21]; while(cin >> m >> n) { if(m == 0 || n == 0) { break; } for(i = 0; i < n; i++) { cin >> str; for(j = 0; j < m; j++) { if(str[j] == '@') { sr = i; sl = j; visited[i][j] = 1; } else if(str[j] == '.') { visited[i][j] = 0; } else { visited[i][j] = 1; } } } int count = BFS(); cout << count << endl; } return 0; } int BFS() { int i, count; queue Q; nodeN, temp; N.r = sr; N.l = sl; count = 1; Q.push(N); while(!Q.empty()) { temp = Q.front(); Q.pop(); for(i = 0; i < 4; i++) { N = temp; N.r += dir[0][i]; N.l += dir[1][i]; if(N.r < 0 || N.r >= n || N.l < 0 || N.l >= m) { continue; } else { if(!visited[N.r][N.l]) { count++; visited[N.r][N.l] = 1; Q.push(N); } } } } return count;}