結果
問題 | No.1612 I hate Construct a Palindrome |
ユーザー |
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提出日時 | 2022-08-12 07:17:14 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 137 ms / 2,000 ms |
コード長 | 10,504 bytes |
コンパイル時間 | 2,405 ms |
コンパイル使用メモリ | 214,708 KB |
最終ジャッジ日時 | 2025-01-30 20:20:28 |
ジャッジサーバーID (参考情報) |
judge4 / judge5 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 36 |
ソースコード
// >>> TEMPLATES#include <bits/stdc++.h>using namespace std;using ll = long long;using ld = long double;using i32 = int32_t;using i64 = int64_t;using u32 = uint32_t;using u64 = uint64_t;#define int llusing pii = pair<int, int>;#define rep(i, n) for (int i = 0; i < (int)(n); i++)#define rep1(i, n) for (int i = 1; i <= (int)(n); i++)#define repR(i, n) for (int i = (int)(n)-1; i >= 0; i--)#define rep1R(i, n) for (int i = (int)(n); i >= 1; i--)#define loop(i, a, B) for (int i = a; i B; i++)#define loopR(i, a, B) for (int i = a; i B; i--)#define all(x) begin(x), end(x)#define allR(x) rbegin(x), rend(x)#define pb push_back#define eb emplace_back#define fst first#define snd secondtemplate <class Int> auto constexpr inf_ = numeric_limits<Int>::max()/2-1;auto constexpr INF32 = inf_<int32_t>;auto constexpr INF64 = inf_<int64_t>;auto constexpr INF = inf_<int>;#ifdef LOCAL#include "debug.hpp"#define oj_local(x, y) (y)#else#define dump(...) (void)(0)#define debug if (0)#define oj_local(x, y) (x)#endiftemplate <class T, class Comp> struct pque : priority_queue<T, vector<T>, Comp> { vector<T> &data() { return this->c; } void clear() { this->c.clear(); } };template <class T> using pque_max = pque<T, less<T>>;template <class T> using pque_min = pque<T, greater<T>>;template <class T, class = typename T::iterator, enable_if_t<!is_same<T, string>::value, int> = 0>ostream& operator<<(ostream& os, T const& a) { bool f = true; for (auto const& x : a) os << (f ? "" : " ") << x, f = false; return os; }template <class T, size_t N, enable_if_t<!is_same<T, char>::value, int> = 0>ostream& operator<<(ostream& os, const T (&a)[N]) { bool f = true; for (auto const& x : a) os << (f ? "" : " ") << x, f = false; return os; }template <class T, class = decltype(begin(declval<T&>())), class = typename enable_if<!is_same<T, string>::value>::type>istream& operator>>(istream& is, T &a) { for (auto& x : a) is >> x; return is; }template <class T, class S> ostream& operator<<(ostream& os, pair<T, S> const& p) { return os << p.first << " " << p.second; }template <class T, class S> istream& operator>>(istream& is, pair<T, S>& p) { return is >> p.first >> p.second; }template <class... T> ostream& operator<<(ostream& os, tuple<T...> const& t){ bool f = true; apply([&](auto&&... x) { ((os << (f ? f = false, "" : " ") << x), ...); }, t); return os; }template <class... T> istream& operator>>(istream& is, tuple<T...>& t) { apply([&](auto&&... x) { ((is >> x), ...); }, t); return is; }struct IOSetup { IOSetup() { cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(15); } } iosetup;template <class F> struct FixPoint : private F {constexpr FixPoint(F&& f) : F(forward<F>(f)) {}template <class... T> constexpr auto operator()(T&&... x) const { return F::operator()(*this, forward<T>(x)...); }};struct MakeFixPoint { template <class F> constexpr auto operator|(F&& f) const { return FixPoint<F>(forward<F>(f)); } };#define def(name, ...) auto name = MakeFixPoint() | [&](auto &&name, __VA_ARGS__)template <class T, size_t d> struct vec_impl {using type = vector<typename vec_impl<T, d-1>::type>;template <class... U> static type make_v(size_t n, U&&... x) { return type(n, vec_impl<T, d-1>::make_v(forward<U>(x)...)); }};template <class T> struct vec_impl<T, 0> { using type = T; static type make_v(T const& x = {}) { return x; } };template <class T, size_t d = 1> using vec = typename vec_impl<T, d>::type;template <class T, size_t d = 1, class... Args> auto make_v(Args&&... args) { return vec_impl<T, d>::make_v(forward<Args>(args)...); }template <class T> void quit(T const& x) { cout << x << '\n'; exit(0); }template <class T, class U> constexpr bool chmin(T& x, U const& y) { if (x > (T)y) { x = (T)y; return true; } return false; }template <class T, class U> constexpr bool chmax(T& x, U const& y) { if (x < (T)y) { x = (T)y; return true; } return false; }template <class It> constexpr auto sumof(It b, It e) { return accumulate(b, e, typename iterator_traits<It>::value_type{}); }template <class T, class = decltype(begin(declval<T&>()))> constexpr auto min(T const& a) { return *min_element(begin(a), end(a)); }template <class T, class = decltype(begin(declval<T&>()))> constexpr auto max(T const& a) { return *max_element(begin(a), end(a)); }template <class T> constexpr T min(set<T> const& st) { assert(st.size()); return *st.begin(); }template <class T> constexpr T max(set<T> const& st) { assert(st.size()); return *prev(st.end()); }template <class T> constexpr T min(multiset<T> const& st) { assert(st.size()); return *st.begin(); }template <class T> constexpr T max(multiset<T> const& st) { assert(st.size()); return *prev(st.end()); }constexpr ll max(signed x, ll y) { return max<ll>(x, y); }constexpr ll max(ll x, signed y) { return max<ll>(x, y); }constexpr ll min(signed x, ll y) { return min<ll>(x, y); }constexpr ll min(ll x, signed y) { return min<ll>(x, y); }template <class T> int sz(T const& x) { return x.size(); }template <class C, class T> int lbd(C const& v, T const& x) { return lower_bound(begin(v), end(v), x)-begin(v); }template <class C, class T> int ubd(C const& v, T const& x) { return upper_bound(begin(v), end(v), x)-begin(v); }constexpr ll mod(ll x, ll m) { assert(m > 0); return (x %= m) < 0 ? x+m : x; }constexpr ll div_floor(ll x, ll y) { assert(y != 0); return x/y - ((x^y) < 0 and x%y); }constexpr ll div_ceil(ll x, ll y) { assert(y != 0); return x/y + ((x^y) > 0 and x%y); }constexpr int dx[] = { 1, 0, -1, 0, 1, -1, -1, 1 };constexpr int dy[] = { 0, 1, 0, -1, 1, 1, -1, -1 };auto four_nbd(int n, int m) {static vector<pair<int, int>> v;return [n, m](int i, int j) {const int dx[] = { 1, 0, -1, 0 }, dy[] = { 0, 1, 0, -1 };v.clear();rep (dir, 4) {int ni = i+dx[dir], nj = j+dy[dir];if (0 <= ni and ni < n and 0 <= nj and nj < m) {v.emplace_back(ni, nj);}}return v;};};template <class Comp> vector<int> iota(int n, Comp comp) {vector<int> idx(n);iota(begin(idx), end(idx), 0);stable_sort(begin(idx), end(idx), comp);return idx;}constexpr int popcnt(ll x) { return __builtin_popcountll(x); }mt19937_64 seed_{random_device{}()};template <class Int> Int rand(Int a, Int b) { return uniform_int_distribution<Int>(a, b)(seed_); }i64 irand(i64 a, i64 b) { return rand<i64>(a, b); } // [a, b]u64 urand(u64 a, u64 b) { return rand<u64>(a, b); } //template <class It> void shuffle(It l, It r) { shuffle(l, r, seed_); }template <class V> V &operator--(V &v) { for (auto &x : v) --x; return v; }template <class V> V &operator++(V &v) { for (auto &x : v) ++x; return v; }bool next_product(vector<int> &v, int m) {repR (i, v.size()) if (++v[i] < m) return true; else v[i] = 0;return false;}bool next_product(vector<int> &v, vector<int> const& s) {repR (i, v.size()) if (++v[i] < s[i]) return true; else v[i] = 0;return false;}template <class vec> int sort_unique(vec &v) {sort(begin(v), end(v));v.erase(unique(begin(v), end(v)), end(v));return v.size();}template <class It> auto prefix_sum(It l, It r) {vector<typename It::value_type> s = { 0 };while (l != r) s.emplace_back(s.back() + *l++);return s;}template <class It> auto suffix_sum(It l, It r) {vector<typename It::value_type> s = { 0 };while (l != r) s.emplace_back(*--r + s.back());reverse(s.begin(), s.end());return s;}template <class T> T pop(vector<T> &a) { auto x = a.back(); a.pop_back(); return x; }template <class T> T pop_back(vector<T> &a) { auto x = a.back(); a.pop_back(); return x; }template <class T, class V, class C> T pop(priority_queue<T, V, C> &a) { auto x = a.top(); a.pop(); return x; }template <class T> T pop(queue<T> &a) { auto x = a.front(); a.pop(); return x; }template <class T> T pop_front(deque<T> &a) { auto x = a.front(); a.pop_front(); return x; }template <class T> T pop_back(deque<T> &a) { auto x = a.back(); a.pop_back(); return x; }template <class T> T pop_front(set<T> &a) { auto x = *a.begin(); a.erase(a.begin()); return x; }template <class T> T pop_back(set<T> &a) { auto it = prev(a.end()); auto x = *it; a.erase(it); return x; }template <class T> T pop_front(multiset<T> &a) { auto it = a.begin(); auto x = *it; a.erase(it); return x; }template <class T> T pop_back(multiset<T> &a) { auto it = prev(a.end()); auto x = *it; a.erase(it); return x; }// <<<int32_t main() {int n, m; cin >> n >> m;struct edge {int from, to, id;char c;};vector<vector<edge>> g(n);rep (i, m) {int x, y; cin >> x >> y; --x, --y;char c; cin >> c;g[x].pb({x, y, i, c});g[y].pb({y, x, i, c});}auto e = g[0][0];edge f = { -1, -1, -1, 0 };[&]() {repR (x, n) {for (auto ee : g[x]) {if (e.c != ee.c) {f = ee;return;}}}quit(-1);}();dump(f);auto bfs = [&](int x, int y) -> vector<edge> {if (x == y) return {};queue<int> q;q.push(x);vector<int> dist(n, INF);vector<edge> pre(n, edge { -1, -1, -1, 0 });dist[x] = 0;while (q.size()) {int x = pop(q);for (auto [_, y, id, c] : g[x]) {if (chmin(dist[y], dist[x] + 1)) {pre[y] = edge { _, y, id, c };q.push(y);}}}vector<edge> ans;int now = y;while (now != x) {auto e = pre[now];ans.eb(e);now = e.from;}reverse(all(ans));dump(x, y, ans);return ans;};vector<edge> ans;ans.eb(e);for (auto ee : bfs(e.to, f.from)) ans.eb(ee);ans.eb(f);for (auto ee : bfs(f.to, n-1)) ans.eb(ee);dump(ans);auto pal = [&](vector<edge> ans) {string s;for (auto [from, to, id, c] : ans) {s += c;}return equal(all(s), s.rbegin());};if (pal(ans)) {dump(ans);ans.insert(ans.begin(), e);ans.insert(ans.begin(), e);}assert(not pal(ans));cout << ans.size() << '\n';for (auto [from, to, id, v] : ans) cout << id+1 << '\n';assert(sz(ans) <= 2*n);}