POJ 1979 解题报告

这道题是简单的DFS。感觉c++输入比较头疼。

1979Accepted728K0MSG++1846B

/* ID: thestor1 LANG: C++ TASK: poj1979 */#include <iostream>#include <fstream>#include <cmath>#include <cstdio>#include <cstring>#include <limits>#include <string>#include <vector>#include <list>#include <set>#include <map>#include <queue>#include <stack>#include <algorithm>#include <cassert>using namespace std;const int MAXW = 20;const int MAXH = 20;int dr[4] = {-1, 0, 1, 0}, dc[4] = {0, 1, 0, -1};void DFS(int r, int c, const std::vector<string> &data, std::vector<std::vector<bool> > &visited, int &cnt, const int H, const int W){cnt++;visited[r][c] = true;// cout << "[debug]data[" << r << "][" << c << "]:" << data[r][c] << endl;int nr, nc;for (int d = 0; d < 4; ++d){nr = r + dr[d], nc = c + dc[d];if (0 <= nr && nr < H && 0 <= nc && nc < W && !visited[nr][nc] && data[nr][nc] == '.'){DFS(nr, nc, data, visited, cnt, H, W);}}}int main(){std::ios::sync_with_stdio(false);int W, H;std::vector<string> data(MAXH, string(MAXW, '.'));std::vector<std::vector<bool> > visited(MAXH, std::vector<bool>(MAXW, false));string line;int x, y;while (cin >> W >> H && W){// cout << "H: " << H << ", W: " << W << endl;for (int h = 0; h < H;){getline(cin, line);if (!line.size()){continue;}// cout << "[debug]line:[" << line << "]" << endl;for (int w = 0; w < W; ++w){data[h][w] = line[w];visited[h][w] = false;if (line[w] == '@'){x = h;y = w;}}++h;}// for (int r = 0; r < H; ++r)// {// for (int c = 0; c < W; ++c)// {// cout << data[r][c];// }// cout << endl;// }int cnt = 0;DFS(x, y, data, visited, cnt, H, W);cout << cnt << endl;}return 0;  }