結果
問題 | No.2855 Move on Grid |
ユーザー |
👑 |
提出日時 | 2024-08-25 13:58:37 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 957 ms / 3,000 ms |
コード長 | 5,221 bytes |
コンパイル時間 | 4,651 ms |
コンパイル使用メモリ | 269,148 KB |
最終ジャッジ日時 | 2025-02-24 01:02:44 |
ジャッジサーバーID (参考情報) |
judge2 / judge5 |
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ファイルパターン | 結果 |
---|---|
other | AC * 40 |
ソースコード
#include<bits/stdc++.h>#include<atcoder/all>#define rep(i,n) for(int i=0;i<n;i++)using namespace std;using namespace atcoder;typedef long long ll;typedef vector<int> vi;typedef vector<long long> vl;typedef vector<vector<int>> vvi;typedef vector<vector<long long>> vvl;typedef long double ld;typedef pair<int, int> P;ostream& operator<<(ostream& os, const modint& a) {os << a.val(); return os;}template <int m> ostream& operator<<(ostream& os, const static_modint<m>& a) {os << a.val(); return os;}template <int m> ostream& operator<<(ostream& os, const dynamic_modint<m>& a) {os << a.val(); return os;}template<typename T> istream& operator>>(istream& is, vector<T>& v){int n = v.size(); assert(n > 0); rep(i, n) is >> v[i]; return is;}template<typename U, typename T> ostream& operator<<(ostream& os, const pair<U, T>& p){os << p.first << ' ' << p.second; return os;}template<typename T> ostream& operator<<(ostream& os, const vector<T>& v){int n = v.size(); rep(i, n) os << v[i] << (i == n - 1 ? "\n" : " "); returnos;}template<typename T> ostream& operator<<(ostream& os, const vector<vector<T>>& v){int n = v.size(); rep(i, n) os << v[i] << (i == n - 1 ? "\n" : "");return os;}template<typename T> ostream& operator<<(ostream& os, const set<T>& se){for(T x : se) os << x << " "; os << "\n"; return os;}template<typename T> ostream& operator<<(ostream& os, const unordered_set<T>& se){for(T x : se) os << x << " "; os << "\n"; return os;}template<typename S, auto op, auto e> ostream& operator<<(ostream& os, const atcoder::segtree<S, op, e>& seg){int n = seg.max_right(0, [](S){returntrue;}); rep(i, n) os << seg.get(i) << (i == n - 1 ? "\n" : " "); return os;}template<typename S, auto op, auto e, typename F, auto mapping, auto composition, auto id> ostream& operator<<(ostream& os, const atcoder::lazy_segtree<S, op, e, F, mapping, composition, id>& seg){int n = seg.max_right(0, [](S){return true;}); rep(i, n) os << seg.get(i) << (i == n- 1 ? "\n" : " "); return os;}template<typename T> void chmin(T& a, T b){a = min(a, b);}template<typename T> void chmax(T& a, T b){a = max(a, b);}const int INF = 1000000000;struct Edge_BFS01{int from, to;int cost;Edge_BFS01(int from, int to, int cost) : from(from), to(to), cost(cost) {};};struct BFS01{int n, m;vector<bool> initialized;vector<Edge_BFS01> E;vector<vector<int>> G;map<int, vector<int>> dist;map<int, vector<int>> idx;BFS01(int _n) : n(_n), m(0), initialized(n, false), G(n){}void add_edge(int from, int to, int cost){assert(cost == 0 or cost == 1);Edge_BFS01 e(from, to, cost);E.push_back(e);G[from].emplace_back(m);m++;}void add_grid(int h, int w, vector<string> s){assert(int(s.size()) == h);assert(int(s[0].size()) == w);rep(y, h){rep(x, w - 1){if(s[y][x] != '#' and s[y][x + 1] != '#'){add_edge(y * w + x, y * w + (x + 1), 1);add_edge(y * w + (x + 1), y * w + x, 1);}}}rep(x, w){rep(y, h - 1){if(s[y][x] != '#' and s[y + 1][x] != '#'){add_edge(y * w + x, (y + 1) * w + x, 1);add_edge((y + 1) * w + x, y * w + x, 1);}}}}void calc(int s){initialized[s] = true;dist[s] = vector<int>(n, INF);idx[s] = vector<int>(n, -1);deque<tuple<int, int ,int>> de;de.emplace_back(0, s, -1);while(de.size()){auto [cost, from, index] = de.front(); de.pop_front();if(dist[s][from] <= cost) continue;dist[s][from] = cost;idx[s][from] = index;for(int index : G[from]){int to = E[index].to;int cost_plus = E[index].cost;if(dist[s][to] <= cost + cost_plus) continue;if(cost_plus == 0) de.emplace_front(cost + cost_plus, to, index);if(cost_plus == 1) de.emplace_back(cost + cost_plus, to, index);}}}int farthest(int s){if(!initialized[s]) calc(s);int idx = 0;rep(i, n) if(dist[s][i] > dist[s][idx]) idx = i;return idx;}int get_dist(int s, int t){if(!initialized[s]) calc(s);return dist[s][t];}vi restore(int s, int t){if(!initialized[s]) calc(s);if(dist[s][t] == INF) return vi(0);vi res;while(idx[s][t] != -1){auto e = E[idx[s][t]];res.push_back(idx[s][t]);t = e.from;}reverse(res.begin(), res.end());return res;}};int main(){int n, m, k;cin >> n >> m >> k;vector<vector<int>> a(n, vector<int>(m));cin >> a;int ok = 0, ng = INF + 1;while(ng - ok > 1){int mid = (ok + ng) / 2;BFS01 graph(n * m + 1);int sv = n * m;rep(y, n) rep(x, m - 1){{int cost = 0;if(a[y][x + 1] < mid) cost = 1;graph.add_edge(y * m + x, y * m + (x + 1), cost);}{int cost = 0;if(a[y][x] < mid) cost = 1;graph.add_edge(y * m + (x + 1), y * m + x, cost);}}rep(y, n - 1) rep(x, m){{int cost = 0;if(a[y + 1][x] < mid) cost = 1;graph.add_edge(y * m + x, (y + 1) * m + x, cost);}{int cost = 0;if(a[y][x] < mid) cost = 1;graph.add_edge((y + 1) * m + x, y * m + x, cost);}}{{int cost = 0;if(a[0][0] < mid) cost = 1;graph.add_edge(sv, 0, cost);}}int tot = graph.get_dist(sv, n * m - 1);if(tot <= k) ok = mid;else ng = mid;}cout << ok << "\n";return 0;}