Submission #1166038

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Source Code Expand

#include "bits/stdc++.h"
using namespace std;
#ifdef _DEBUG
#include "dump.hpp"
#else
#define dump(...)
#endif

//#define int long long
#define rep(i,a,b) for(int i=(a);i<(b);i++)
#define rrep(i,a,b) for(int i=(b)-1;i>=(a);i--)
#define all(c) begin(c),end(c)
const int INF = sizeof(int) == sizeof(long long) ? 0x3f3f3f3f3f3f3f3fLL : 0x3f3f3f3f;
const int MOD = (int)(1e9) + 7;
template<class T> bool chmax(T &a, const T &b) { if (a < b) { a = b; return true; } return false; }
template<class T> bool chmin(T &a, const T &b) { if (b < a) { a = b; return true; } return false; }

int di[4] = { 0,1,0,-1 };
int dj[4] = { 1,0,-1,0 };
char dir[4] = { 'R','D','L','U' };


int H, W, K, sr, sc;
char s[51][51];
int N;
int fr[2510], fc[2510], F[2510], D[2510];

bool inrange(int i, int j) { return i >= 0 && i < H && j >= 0 && j < W; }

void output(string ans) {
	if (ans.size() >= 2500) {
		cout << ans.substr(0, 2500) << endl;
	}
	else {
		ans += string(2500 - ans.size(), '-');
		cout << ans << endl;
	}
}

using Weight = int;
using Flow = int;
struct Edge {
	int s, d; Weight w; Flow c;
	Edge() {};
	Edge(int s, int d, Weight w = 1) : s(s), d(d), w(w), c(w) {};
	bool operator<(const Edge &e)const { return w < e.w; }
};
using Edges = vector<Edge>;
using Graph = vector<Edges>;
using Array = vector<Weight>;
using Matrix = vector<Array>;

inline ostream &operator<<(ostream &os, const Edge &e) { return (os << '(' << e.s << ", " << e.d << ", " << e.w << ')'); }

void add_edge(Graph &g, int a, int b, Weight w = 1) {
	g[a].emplace_back(a, b, w);
	g[b].emplace_back(b, a, w);
}
void add_arc(Graph &g, int s, int d, Weight w = 1) { g[s].emplace_back(s, d, w); }

//未探索, 探索中, 探索済
enum { WHITE, GRAY, BLACK };

//単一始点最短経路(負閉路なし)
//Dijkstra O((E+V)logV)
//dist: 始点から各頂点までの最短距離
//戻り値: 最短経路木の親頂点(根は-1)
vector<int> dijkstra(const Graph &g, int s, Array &dist) {
	int n = g.size();
	vector<int> color(n, WHITE); color[s] = GRAY;
	vector<int> prev(n, -1);
	dist.assign(n, INF); dist[s] = 0;
	using State = tuple<Weight, int, int>; //始点からの最短距離 子 親
	priority_queue<State, vector<State>, greater<State>> pq; pq.emplace(0, s, -1);
	while (pq.size()) {
		Weight d; int v, u; tie(d, v, u) = pq.top(); pq.pop(); //distが最小となるStateを取り出す
		if (dist[v] < d)continue; //すでに最短でなければ無視
		color[v] = BLACK; prev[v] = u;
		for (auto &e : g[v]) {
			if (color[e.d] == BLACK)continue;
			if (dist[e.d] > dist[v] + e.w) {
				dist[e.d] = dist[v] + e.w;
				pq.emplace(dist[e.d], e.d, v);
				color[e.d] = GRAY;
			}
		}
	}
	return prev;
}

auto idx = [&](int i, int j) {return i*W + j; };

//二次元配列からGraphを生成
Graph build(const vector<vector<char>> &v) {
	const int H = v.size(), W = v[0].size();
	static const int di[4] = { 1,0,-1,0 }, dj[4] = { 0,1,0,-1 };
	auto inrange = [&](int i, int j) { return i >= 0 && i < H && j >= 0 && j < W; };
	Graph g(H*W);
	rep(i, 0, H)rep(j, 0, W) {
		if (v[i][j] == '#')continue;
		rep(k, 0, 4) {
			int ni = i + di[k], nj = j + dj[k];
			if (!inrange(ni, nj))continue;
			if (v[ni][nj] == '#')continue;
			int s = idx(i, j), d = idx(ni, nj);
			add_arc(g, s, d);
		}
	}
	return g;
}

struct UnionFind {
	vector<int> parent;
	int size;
	UnionFind(int n) :parent(n, -1), size(n) {}
	bool unite(int x, int y) {
		x = root(x); y = root(y);
		if (x == y)return false;
		if (size_of(x) < size_of(y))swap(x, y);
		parent[x] += parent[y]; parent[y] = x; size--;
		return true;
	}
	bool same(int x, int y) { return root(x) == root(y); }
	int root(int x) { return parent[x] < 0 ? x : parent[x] = root(parent[x]); }
	int size_of(int x) { return -parent[root(x)]; }
};

string bfs(int si, int sj, int gi, int gj) {
	using P = tuple<int, int, string>;
	queue<P> q;
	vector<vector<int>> d(H, vector<int>(W, INF));
	q.emplace(si, sj, "");
	auto inrange = [&](int i, int j) { return i >= 0 && i < H && j >= 0 && j < W; };
	while (q.size()) {
		int ci, cj; string r; tie(ci, cj, r) = q.front(); q.pop();
		if (ci == gi&&cj == gj) {
			s[gi][gj] = '.';
			return r;
		}
		if (!inrange(ci, cj))continue;
		if (s[ci][cj] == '#')continue;
		//else if (s[ci][cj] == 'o')continue;
		if (d[ci][cj] < INF)continue;
		d[ci][cj] = r.size();
		rep(i, 0, 4) {
			q.emplace(ci + di[i], cj + dj[i], r + dir[i]);
		}
	}
	return "";
}

signed main() {

	//auto bfs = [&](int si, int sj, int gi, int gj) {
	//	using P = tuple<int, int, string>;
	//	queue<P> q;
	//	vector<vector<int>> d(H, vector<int>(W, INF));
	//	q.emplace(si, sj, "");
	//	auto inrange = [&](int i, int j) { return i >= 0 && i < H && j >= 0 && j < W; };
	//	while (q.size()) {
	//		int ci, cj; string r; tie(ci, cj, r) = q.front(); q.pop();
	//		if (ci == gi&&cj == gj)return make_pair(score, r);
	//		if (!inrange(ci, cj))continue;
	//		if (s[ci][cj] == '#')continue;
	//		if (d[ci][cj] < INF)continue;
	//		d[ci][cj] = r.size();
	//		rep(i, 0, 4) {
	//			q.emplace(ci + di[i], cj + dj[i], r + dir[i]);
	//		}
	//	}
	//	return make_pair(0, "");
	//};

	cin.tie(0);
	ios::sync_with_stdio(false);
	cin >> H >> W >> K >> sr >> sc; sr--, sc--;
	vector<vector<char>> v(H, vector<char>(W));
	rep(i, 0, H)rep(j, 0, W) {
		cin >> s[i][j];
		v[i][j] = s[i][j];
	}
	cin >> N;
	rep(i, 0, N) {
		cin >> fr[i] >> fc[i] >> F[i] >> D[i];
		fr[i]--, fc[i]--;
		s[fr[i]][fc[i]] = 'o';
	}
	fr[N] = sr, fc[N] = sc;
	N++;
	Graph g1 = build(v);
	Matrix C(N, Array(N));
	Graph g2(N);
	rep(i, 0, N) {
		Array dist;
		int s = idx(fr[i], fc[i]);
		dijkstra(g1, s, dist);
		rep(j, i + 1, N) {
			int d = idx(fr[j], fc[j]);
			add_edge(g2, i, j, dist[d]);
			C[i][j] = C[j][i] = dist[d];
		}
	}
	int s = N - 1;
	string ans = "";
	vector<int> flag(N);
	rep(a, 0, N) {
		flag[s] = true;
		int d = -1;
		Weight mini = INF;
		rep(j, 0, N) {
			if (s == j)continue;
			if (flag[j])continue;
			int t = ans.size();
			if (F[j] - D[j] * (C[s][j] + t) <= 0)continue;
			rep(k, 0, N) {
				if (j == k)continue;
				if (flag[k])continue;
				if (F[k] - D[k] * (C[s][j] + C[j][k] + t) <= 0)continue;
				if (chmin(mini, C[s][j] + C[j][k])) {
					d = j;
					//dump(s, j, k, C[s][j], C[j][k]);
					//dump(mini);
				}
			}
		}
		dump(d);
		if (d == -1)break;
		dump(ans.size(), fr[s], fc[s], fr[d], fc[d]);
		ans += bfs(fr[s], fc[s], fr[d], fc[d]);
		s = d;
	}
	output(ans);
	return 0;
}

Submission Info

Judge Result