File size: 6,643 Bytes
14c9c2b | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 | #include <vector>
#include <numeric>
#include <algorithm>
#include <set>
#include <cmath>
#include <random>
#include <chrono>
using namespace std;
static mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
static bool adj[45][45];
static vector<int> adj_list[45];
static int N_glob, M_glob;
struct Candidate {
vector<int> row;
int score;
};
inline bool is_adj_or_same(int u, int v) {
if (u == v) return true;
return adj[u][v];
}
std::vector<std::vector<int>> create_map(int N, int M,
std::vector<int> A, std::vector<int> B) {
N_glob = N;
M_glob = M;
for(int i=1; i<=N; ++i) {
for(int j=1; j<=N; ++j) adj[i][j] = false;
adj_list[i].clear();
}
for(int i=0; i<M; ++i) {
int u = A[i];
int v = B[i];
adj[u][v] = adj[v][u] = true;
adj_list[u].push_back(v);
adj_list[v].push_back(u);
}
int lower_bound_K = ceil(sqrt(M/2.0));
int node_bound = ceil(sqrt(N));
int start_W = max({lower_bound_K, node_bound, 1});
if (start_W < 2 && N > 1) start_W = 2;
auto start_time = chrono::steady_clock::now();
for (int W = start_W; W <= 240; ++W) {
for (int attempt = 0; attempt < 5; ++attempt) {
if (chrono::duration_cast<chrono::milliseconds>(chrono::steady_clock::now() - start_time).count() > 1900) {
// Time limit approaching, stop trying
break;
}
vector<vector<int>> grid;
set<pair<int,int>> covered_edges;
set<int> covered_nodes;
bool possible = true;
for (int r = 0; r < 240; ++r) {
if (covered_edges.size() == M && covered_nodes.size() == N) {
int H = grid.size();
int K = max(W, H);
vector<vector<int>> final_map(K, vector<int>(K));
for(int i=0; i<K; ++i) {
const vector<int>& src_row = (i < H) ? grid[i] : grid[H-1];
for(int j=0; j<K; ++j) {
final_map[i][j] = (j < W) ? src_row[j] : src_row[W-1];
}
}
return final_map;
}
if (r >= 240) { possible = false; break; }
int beam_width = 40;
vector<Candidate> beam;
beam.push_back({{}, 0});
for (int c = 0; c < W; ++c) {
vector<Candidate> next_beam;
int up_node = (r > 0) ? grid[r-1][c] : -1;
for (const auto& cand : beam) {
int left_node = (c > 0) ? cand.row.back() : -1;
vector<int> possibilities;
auto check_and_add = [&](int v) {
if (up_node != -1 && !is_adj_or_same(v, up_node)) return;
possibilities.push_back(v);
};
if (left_node != -1) {
check_and_add(left_node);
for(int v : adj_list[left_node]) check_and_add(v);
} else if (up_node != -1) {
check_and_add(up_node);
for(int v : adj_list[up_node]) check_and_add(v);
} else {
// Random start
for(int k=0; k<10; ++k) {
possibilities.push_back((rng() % N) + 1);
}
}
if (possibilities.empty()) continue;
sort(possibilities.begin(), possibilities.end());
possibilities.erase(unique(possibilities.begin(), possibilities.end()), possibilities.end());
shuffle(possibilities.begin(), possibilities.end(), rng);
if (possibilities.size() > 8) possibilities.resize(8);
for (int v : possibilities) {
int score = cand.score;
if (covered_nodes.find(v) == covered_nodes.end()) score += 5000;
if (left_node != -1 && left_node != v) {
int mn = min(left_node, v), mx = max(left_node, v);
if (covered_edges.find({mn, mx}) == covered_edges.end()) score += 100;
}
if (up_node != -1 && up_node != v) {
int mn = min(up_node, v), mx = max(up_node, v);
if (covered_edges.find({mn, mx}) == covered_edges.end()) score += 100;
}
Candidate next = cand;
next.row.push_back(v);
next.score = score;
next_beam.push_back(next);
}
}
if (next_beam.empty()) {
beam.clear();
break;
}
sort(next_beam.begin(), next_beam.end(), [](const Candidate& a, const Candidate& b){
return a.score > b.score;
});
if (next_beam.size() > beam_width) next_beam.resize(beam_width);
beam = next_beam;
}
if (beam.empty()) {
possible = false;
break;
}
const auto& best_row = beam[0].row;
grid.push_back(best_row);
for (int c = 0; c < W; ++c) {
int v = best_row[c];
covered_nodes.insert(v);
if (c > 0) {
int u = best_row[c-1];
if (u != v) covered_edges.insert({min(u,v), max(u,v)});
}
if (r > 0) {
int u = grid[r-1][c];
if (u != v) covered_edges.insert({min(u,v), max(u,v)});
}
}
}
}
}
return {};
} |