結果
| 問題 | No.2238 Rock and Hole |
| ユーザー |
 t98slider
|
| 提出日時 | 2023-03-04 04:16:25 |
| 言語 | C++14 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 44 ms / 3,000 ms |
| コード長 | 5,833 bytes |
| コンパイル時間 | 1,713 ms |
| コンパイル使用メモリ | 182,680 KB |
| 実行使用メモリ | 16,024 KB |
| 最終ジャッジ日時 | 2024-09-18 00:55:50 |
| 合計ジャッジ時間 | 2,798 ms |
|
ジャッジサーバーID （参考情報） |
judge6 / judge1 |
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| ファイルパターン | 結果 |
|---|---|
| other | AC * 24 |
ソースコード
#include <bits/stdc++.h>using namespace std;using ll = long long;template <class T> struct simple_queue {std::vector<T> payload;int pos = 0;void reserve(int n) { payload.reserve(n); }int size() const { return int(payload.size()) - pos; }bool empty() const { return pos == int(payload.size()); }void push(const T& t) { payload.push_back(t); }T& front() { return payload[pos]; }void clear() {payload.clear();pos = 0;}void pop() { pos++; }};template <class Cap> struct mf_graph {public:mf_graph() : _n(0) {}mf_graph(int n) : _n(n), g(n) {}int add_edge(int from, int to, Cap cap) {assert(0 <= from && from < _n);assert(0 <= to && to < _n);assert(0 <= cap);int m = int(pos.size());pos.push_back({from, int(g[from].size())});g[from].push_back(_edge{to, int(g[to].size()), cap});g[to].push_back(_edge{from, int(g[from].size()) - 1, 0});return m;}struct edge {int from, to;Cap cap, flow;};edge get_edge(int i) {int m = int(pos.size());assert(0 <= i && i < m);auto _e = g[pos[i].first][pos[i].second];auto _re = g[_e.to][_e.rev];return edge{pos[i].first, _e.to, _e.cap + _re.cap, _re.cap};}std::vector<edge> edges() {int m = int(pos.size());std::vector<edge> result;for (int i = 0; i < m; i++) {result.push_back(get_edge(i));}return result;}void change_edge(int i, Cap new_cap, Cap new_flow) {int m = int(pos.size());assert(0 <= i && i < m);assert(0 <= new_flow && new_flow <= new_cap);auto& _e = g[pos[i].first][pos[i].second];auto& _re = g[_e.to][_e.rev];_e.cap = new_cap - new_flow;_re.cap = new_flow;}Cap flow(int s, int t) {return flow(s, t, std::numeric_limits<Cap>::max());}Cap flow(int s, int t, Cap flow_limit) {assert(0 <= s && s < _n);assert(0 <= t && t < _n);std::vector<int> level(_n), iter(_n);simple_queue<int> que;auto bfs = [&]() {std::fill(level.begin(), level.end(), -1);level[s] = 0;que.clear();que.push(s);while (!que.empty()) {int v = que.front();que.pop();for (auto e : g[v]) {if (e.cap == 0 || level[e.to] >= 0) continue;level[e.to] = level[v] + 1;if (e.to == t) return;que.push(e.to);}}};auto dfs = [&](auto self, int v, Cap up) {if (v == s) return up;Cap res = 0;int level_v = level[v];for (int& i = iter[v]; i < int(g[v].size()); i++) {_edge& e = g[v][i];if (level_v <= level[e.to] || g[e.to][e.rev].cap == 0) continue;Cap d =self(self, e.to, std::min(up - res, g[e.to][e.rev].cap));if (d <= 0) continue;g[v][i].cap += d;g[e.to][e.rev].cap -= d;res += d;if (res == up) break;}return res;};Cap flow = 0;while (flow < flow_limit) {bfs();if (level[t] == -1) break;std::fill(iter.begin(), iter.end(), 0);while (flow < flow_limit) {Cap f = dfs(dfs, t, flow_limit - flow);if (!f) break;flow += f;}}return flow;}std::vector<bool> min_cut(int s) {std::vector<bool> visited(_n);simple_queue<int> que;que.push(s);while (!que.empty()) {int p = que.front();que.pop();visited[p] = true;for (auto e : g[p]) {if (e.cap && !visited[e.to]) {visited[e.to] = true;que.push(e.to);}}}return visited;}private:int _n;struct _edge {int to, rev;Cap cap;};std::vector<std::pair<int, int>> pos;std::vector<std::vector<_edge>> g;};int main(){ios::sync_with_stdio(false);cin.tie(0);int h, w, cnt = 0;cin >> h >> w;vector<string> A(h);mf_graph<int> g(h * w + 2);int s = h * w, t = s + 1;for(auto &&s : A) cin >> s;for(int y = 0; y < h; y++){for(int x = 0, v = -1; x < w; x++){if(A[y][x] == 'h'){v = y * w + x;continue;}if(v != -1 && A[y][x] == 'r') g.add_edge(y * w + x, v, 1);}for(int x = w - 1, v = -1; x >= 0; x--){if(A[y][x] == 'h'){v = y * w + x;continue;}if(v != -1 && A[y][x] == 'r') g.add_edge(y * w + x, v, 1);}}for(int x = 0; x < w; x++){for(int y = 0, v = -1; y < h; y++){if(A[y][x] == 'h'){v = y * w + x;continue;}if(v != -1 && A[y][x] == 'r') g.add_edge(y * w + x, v, 1);}for(int y = h - 1, v = -1; y >= 0; y--){if(A[y][x] == 'h'){v = y * w + x;g.add_edge(y * w + x, t, 1);continue;}if(A[y][x] == 'r'){g.add_edge(s, y * w + x, 1);cnt++;}if(v != -1 && A[y][x] == 'r')g.add_edge(y * w + x, v, 1);}}cout << (g.flow(s, t) == cnt ? "Yes" : "No") << '\n';}