# 주차장

Created
2021/03/23 01:58
문제 번호
1348
카테고리
그래프
이분탐색
BFS
이분매칭

### Code

@12/28/2020

2288 KB

#### 시간

16 ms
#include <iostream> #include <map> #include <queue> #include <string> #include <vector> int g_row; int g_col; int g_map_size; int g_car_size; int g_parking_size; int g_time; std::string g_map; std::vector<int> g_car; std::map<int, int> g_parking; std::vector<int> g_dist; std::vector<int> g_bipar; std::vector<bool> g_visited; std::vector<std::pair<int, int>> g_dir; std::vector<std::vector<std::pair<int, int>>> g_graph; void pre_setting(void) { std::ios_base::sync_with_stdio(false); std::cin.tie(NULL); std::cout.tie(NULL); } void input_action(void) { int i; std::cin >> g_row >> g_col; g_map_size = g_row * g_col; g_time = -1; g_parking_size = 0; g_map = std::string(g_map_size, 0); i = -1; while (++i < g_map_size) { std::cin >> g_map[i]; if (g_map[i] == 'C') g_car.push_back(i); else if (g_map[i] == 'P') g_parking[i] = g_parking_size++; } g_car_size = g_car.size(); g_dir = { { -1, 0 }, { 1, 0 }, { 0, 1 }, { 0, -1 } }; g_graph = std::vector<std::vector<std::pair<int, int>>>(g_car_size); } void make_dist(int order) { int node; int x; int y; int pos; int i; int n_x; int n_y; int n_pos; std::queue<int> waiting; waiting.push(g_car[order]); g_dist = std::vector<int>(g_map_size, -1); g_dist[g_car[order]] = 0; while (waiting.size()) { node = waiting.front(); waiting.pop(); x = node / g_col; y = node % g_col; pos = x * g_col + y; i = -1; while (++i < 4) { n_x = x + g_dir[i].first; n_y = y + g_dir[i].second; n_pos = n_x * g_col + n_y; if (n_x < 0 || n_y < 0 || n_x >= g_row || n_y >= g_col || g_dist[n_pos] != -1 || g_map[n_pos] == 'X') continue ; if (g_parking.count(n_pos) == 1) { g_graph[order].push_back({ g_parking[n_pos], g_dist[pos] + 1 }); g_time = std::max(g_dist[pos] + 1, g_time); } g_dist[n_pos] = g_dist[pos] + 1; waiting.push(n_pos); } } } bool depth_search(int order, int lim) { if (g_visited[order]) return (false); g_visited[order] = true; for (auto i : g_graph[order]) { if (i.second <= lim && (g_bipar[i.first] == -1 || depth_search(g_bipar[i.first], lim))) { g_bipar[i.first] = order; return (true); } } return (false); } int make_match(int lim) { int i; int cnt; i = -1; cnt = 0; g_bipar = std::vector<int>(g_parking_size, -1); while (++i < g_car_size) { g_visited = std::vector<bool>(g_car_size, false); if (depth_search(i, lim)) ++cnt; } return (cnt); } void binary_search(void) { int l; int r; int m; l = 1; r = g_time; while (l <= r) { m = (l + r) >> 1; if (make_match(m) >= g_car_size) { r = m - 1; } else l = m + 1; } g_time = l; } void output_action(void) { std::cout << g_time; } void solution(void) { int i; input_action(); if (g_car_size == 0) g_time = 0; else if (g_car_size > g_parking_size) g_time = -1; else { i = -1; while (++i < g_car_size) make_dist(i); binary_search(); if (make_match(g_time) != g_car_size) g_time = -1; } output_action(); } int main(void) { pre_setting(); solution(); return (0); }
C++