보물섬

#include <iostream> #include <queue> #include <algorithm> #include <cstring> int N, M; int dx[4] = {0,0,1,-1}; int dy[4] = {1,-1,0,0}; int g_map[51][51]; bool visited[51][51]; int ans_map[51][51]; std::queue<std::pair<int, int> >q; int ans; void input_faster() { std::ios_base::sync_with_stdio(false); std::cin.tie(0); std::cout.tie(0); } void input() { input_faster(); std::cin >> N >> M; std::string tmp; for (int i = 0 ; i < N ; i++) { std::cin >> tmp; for (int j = 0 ; j < M ; j++) g_map[i][j] = tmp[j]; } } void bfs(int y, int x) { int qy, qx, ny, nx; visited[y][x] = 1; q.push({y, x}); ans_map[y][x] = 0; while(!q.empty()) { qy = q.front().first; qx = q.front().second; q.pop(); for (int i = 0 ; i < 4 ; i++) { nx = qx + dx[i]; ny = qy + dy[i]; if (ny < 0 || ny >= N || nx < 0 || nx >= M || visited[ny][nx] || g_map[ny][nx] == 'W') continue; visited[ny][nx] = 1; ans_map[ny][nx] = ans_map[qy][qx] + 1; ans = std::max(ans_map[ny][nx], ans); q.push({ny, nx}); } } } void solve() { for (int i = 0 ; i < N ; i++) for (int j = 0 ; j < M ; j++) if (g_map[i][j] == 'L') { std::memset(visited, 0, sizeof(visited)); std::memset(ans_map, 0, sizeof(ans_map)); bfs(i, j); } } void print_val() { std::cout << ans; } int main() { input(); solve(); print_val(); return (0); }