結果

問題 No.1612 I hate Construct a Palindrome
ユーザー haruki_Kharuki_K
提出日時 2022-08-12 07:17:14
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 167 ms / 2,000 ms
コード長 10,504 bytes
コンパイル時間 2,687 ms
コンパイル使用メモリ 221,948 KB
実行使用メモリ 35,008 KB
最終ジャッジ日時 2024-09-22 11:50:05
合計ジャッジ時間 7,675 ms
ジャッジサーバーID
(参考情報)
judge4 / judge5
このコードへのチャレンジ
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テストケース

テストケース表示
入力 結果 実行時間
実行使用メモリ
testcase_00 AC 2 ms
6,812 KB
testcase_01 AC 3 ms
6,944 KB
testcase_02 AC 122 ms
35,008 KB
testcase_03 AC 2 ms
6,944 KB
testcase_04 AC 3 ms
6,944 KB
testcase_05 AC 115 ms
33,984 KB
testcase_06 AC 93 ms
20,512 KB
testcase_07 AC 95 ms
20,336 KB
testcase_08 AC 91 ms
19,768 KB
testcase_09 AC 81 ms
18,312 KB
testcase_10 AC 83 ms
18,176 KB
testcase_11 AC 82 ms
18,304 KB
testcase_12 AC 94 ms
19,308 KB
testcase_13 AC 94 ms
19,296 KB
testcase_14 AC 94 ms
19,272 KB
testcase_15 AC 167 ms
28,540 KB
testcase_16 AC 157 ms
28,608 KB
testcase_17 AC 158 ms
28,584 KB
testcase_18 AC 2 ms
6,944 KB
testcase_19 AC 2 ms
6,940 KB
testcase_20 AC 2 ms
6,940 KB
testcase_21 AC 2 ms
6,944 KB
testcase_22 AC 2 ms
6,940 KB
testcase_23 AC 2 ms
6,944 KB
testcase_24 AC 3 ms
6,944 KB
testcase_25 AC 3 ms
6,940 KB
testcase_26 AC 3 ms
6,940 KB
testcase_27 AC 2 ms
6,940 KB
testcase_28 AC 2 ms
6,940 KB
testcase_29 AC 2 ms
6,940 KB
testcase_30 AC 2 ms
6,940 KB
testcase_31 AC 2 ms
6,944 KB
testcase_32 AC 2 ms
6,944 KB
testcase_33 AC 2 ms
6,940 KB
testcase_34 AC 2 ms
6,940 KB
testcase_35 AC 2 ms
6,944 KB
testcase_36 AC 2 ms
6,944 KB
testcase_37 AC 2 ms
6,944 KB
testcase_38 AC 2 ms
6,944 KB
権限があれば一括ダウンロードができます

ソースコード

diff #

// >>> 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 ll
using 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 second
template <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)
#endif
template <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);
}
0