結果
| 問題 |
No.5020 Averaging
|
| コンテスト | |
| ユーザー |
 Godai Takashina
|
| 提出日時 | 2024-02-25 16:52:18 |
| 言語 | C++17(gcc12) (gcc 12.3.0 + boost 1.87.0) |
| 結果 |
WA
|
| 実行時間 | - |
| コード長 | 7,860 bytes |
| コンパイル時間 | 1,430 ms |
| コンパイル使用メモリ | 112,072 KB |
| 実行使用メモリ | 6,548 KB |
| スコア | 30,157,666 |
| 最終ジャッジ日時 | 2024-02-25 16:54:27 |
| 合計ジャッジ時間 | 52,105 ms |
|
ジャッジサーバーID （参考情報） |
judge12 / judge14 |
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| ファイルパターン | 結果 |
|---|---|
| other | AC * 42 WA * 8 |
ソースコード
#include <iostream>
#include <vector>
#include <random>
#include <chrono>
#include <cmath>
constexpr int max_swap = 50;
static int n;
static std::mt19937 mt(0);
static std::uniform_real_distribution<> uniform(0.,1.);
static std::vector<long> a, b;
using Entry = std::pair<int, int>;
using Solution = std::vector<Entry>;
long calc_score(const Solution& ans, const std::vector<long>& a, const std::vector<long>& b) {
std::vector<long> aa = a;
std::vector<long> bb = b;
for (auto [u,v] : ans) {
long v1 = (aa[u] + aa[v])/2;
long v2 = (bb[u] + bb[v])/2;
aa[u] = v1;
aa[v] = v1;
bb[u] = v2;
bb[v] = v2;
}
double v1 = std::abs(aa[0] - 5*1e17);
double v2 = std::abs(bb[0] - 5*1e17);
long score = 2000000L - 100000L * std::log10(std::max(v1, v2) + 1);
return score;
}
void print_ans(const Solution& ans) {
std::cout << ans.size() << std::endl;
for (auto [u,v] : ans) {
std::cout << u+1 << " " << v+1 << std::endl;
}
}
void debug_print_ans(const Solution& ans) {
for (auto [u,v] : ans) {
std::cerr << "(" << u << "," << v << ") ";
}
std::cerr << "score = " << calc_score(ans, a, b) << std::endl;
}
auto gen_random_ans(int n) {
constexpr int m = 50;
std::vector<Entry> ans;
for (int i = 0; i < m; i++) {
int u, v;
while (true) {
u = mt() % n;
v = mt() % n;
if (u != v) {
break;
}
}
ans.emplace_back(u,v);
}
return ans;
}
auto greedy_ans(int n) {
constexpr int m = 50;
std::vector<Entry> ans;
long best_score = calc_score(ans, a, b);
std::cerr << "initial score: " << best_score << std::endl;
for (int i = 0; i < m; i++) {
/* std::cerr << i << " th iter" << std::endl; */
int u = 0;
int best_v = -1;
for (int v = 1; v < n; v++) {
ans.emplace_back(u,v);
long score = calc_score(ans, a, b);
/* std::cerr << "v, score: " << v << ", " << score << std::endl; */
if (score > best_score) {
best_score = score;
best_v = v;
}
ans.pop_back();
}
/* std::cerr << "best v, score: " << best_v << ", " << best_score << std::endl; */
if (best_v == -1) {
break;
}
else {
ans.emplace_back(u,best_v);
}
}
return ans;
}
auto add_three_swaps(Solution& ans) {
constexpr int m = 50;
long best_score = calc_score(ans, a, b);
for (int u = 1; u < n-1; u++) {
for (int v = u+1; v < n; v++) {
for (int v2 = v+1; v2 < n; v2++) {
ans.push_back(Entry{u,v});
ans.push_back(Entry{u,v2});
ans.push_back(Entry{0,u});
long score = calc_score(ans, a, b);
if (score > best_score) {
best_score = score;
}
else {
ans.pop_back();
ans.pop_back();
ans.pop_back();
}
}
}
}
return ans;
}
auto greedy_iter_three_swaps(int n) {
Solution ans;
while (ans.size() <= max_swap - 4) {
auto size = ans.size();
add_three_swaps(ans);
if (size == ans.size()) { // no pair inserted
break;
}
}
return ans;
}
void annealing(Solution& ans) {
std::cerr << "annealing()" << std::endl;
constexpr int m = 50;
long best_score = calc_score(ans, a, b);
auto start_time = std::chrono::steady_clock::now();
const double duration = 950; // msec
const double start_temp = 10000;
const double end_temp = 100;
/* const long max_iter = 50000000; */
/* for (long iter = 0; iter < max_iter; iter++) { */
/* double temp = start_temp + (end_temp - start_temp) * (static_cast<double>(iter) / max_iter); */
while (true) {
auto time = std::chrono::steady_clock::now();
auto elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(time - start_time).count();
if (elapsed > duration) {
break;
}
double temp = start_temp + (end_temp - start_temp) * (static_cast<double>(elapsed) / duration);
int r = mt() % 2;
// add a random entry
if (r == 0) {
if (ans.size() == m) continue;
int u = mt() % n;
int v = mt() % n;
if (u == v) continue;
int pos = mt() % (ans.size() + 1);
ans.insert(ans.begin() + pos, Entry{u,v});
long score = calc_score(ans, a, b);
double ratio = std::exp((score - best_score) / temp);
double dice = uniform(mt);
if (dice < ratio) {
/* std::cerr << "insert (" << u << ", " << v << ")" << " at " << pos << std::endl; */
/* std::cerr << "score: " << best_score << " -> " << score << std::endl; */
best_score = score;
}
else {
ans.erase(ans.begin() + pos);
}
}
// remove a random entry
if (r == 1) {
if (ans.size() == 0) continue;
int pos = mt() % ans.size();
auto [u,v] = ans[pos];
ans.erase(ans.begin() + pos);
long score = calc_score(ans, a, b);
double ratio = std::exp((score - best_score) / temp);
double dice = uniform(mt);
if (dice < ratio) {
/* std::cerr << "Delete (" << u << ", " << v << ")" << " at " << pos << std::endl; */
/* std::cerr << "score: " << best_score << " -> " << score << std::endl; */
best_score = score;
}
else {
ans.insert(ans.begin() + pos, Entry{u,v});
}
}
// replace an entry with random value
/* if (r == _) { */
/* if (ans.size() == 0) continue; */
/* int pos = mt() % ans.size(); */
/* int new_u = mt() % n; */
/* int new_v = mt() % n; */
/* auto [u,v] = ans[pos]; */
/* ans[pos] = Entry{new_u, new_v}; */
/* long score = calc_score(ans, a, b); */
/* double ratio = std::exp((score - best_score) / temp); */
/* double dice = uniform(mt); */
/* if (dice < ratio) { */
/* best_score = score; */
/* } */
/* else { */
/* ans[pos] = Entry{u,v}; */
/* } */
/* } */
// swap random two entries
/* if (r == _) { */
/* if (ans.size() == 0) continue; */
/* auto i = mt() % ans.size(); */
/* auto j = mt() % ans.size(); */
/* if (i == j) continue; */
/* std::swap(ans[i], ans[j]); */
/* long score = calc_score(ans, a, b); */
/* double ratio = std::exp((score - best_score) / temp); */
/* double dice = uniform(mt); */
/* if (dice < ratio) { */
/* best_score = score; */
/* } */
/* else { */
/* std::swap(ans[i], ans[j]); */
/* } */
/* } */
}
}
int main() {
std::cin >> n;
a.resize(n);
b.resize(n);
for (int i = 0; i < n; i++) {
std::cin >> a[i] >> b[i];
}
auto ans = greedy_iter_three_swaps(n);
std::cerr << "-----------------" << std::endl;
std::cerr << "greedy: ";
debug_print_ans(ans);
std::cerr << "-----------------" << std::endl;
annealing(ans);
std::cerr << "annealing: ";
debug_print_ans(ans);
std::cerr << "-----------------" << std::endl;
std::cerr << "Final score: " << calc_score(ans, a, b) << std::endl;
print_ans(ans);
}