結果
| 問題 | No.1612 I hate Construct a Palindrome |
| ユーザー |
 hitonanode
|
| 提出日時 | 2021-07-21 21:47:23 |
| 言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 187 ms / 2,000 ms |
| コード長 | 13,598 bytes |
| コンパイル時間 | 1,999 ms |
| コンパイル使用メモリ | 166,932 KB |
| 最終ジャッジ日時 | 2025-01-23 03:47:46 |
|
ジャッジサーバーID （参考情報） |
judge5 / judge2 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 3 |
| other | AC * 36 |
コンパイルメッセージ
main.cpp: In function ‘int main()’:
main.cpp:323:38: warning: ‘a1’ may be used uninitialized [-Wmaybe-uninitialized]
323 | auto p01 = graph.retrieve_path(a1);
| ^
main.cpp:312:13: note: ‘a1’ was declared here
312 | int e1, a1, b1;
| ^~
main.cpp:324:16: warning: ‘b1’ may be used uninitialized [-Wmaybe-uninitialized]
324 | graph.solve(b1);
| ~~~~~~~~~~~^~~~
main.cpp:312:17: note: ‘b1’ was declared here
312 | int e1, a1, b1;
| ^~
main.cpp:313:10: warning: ‘c1’ may be used uninitialized [-Wmaybe-uninitialized]
313 | char c1;
| ^~
ソースコード
#include <algorithm>#include <array>#include <bitset>#include <cassert>#include <chrono>#include <cmath>#include <complex>#include <deque>#include <forward_list>#include <fstream>#include <functional>#include <iomanip>#include <ios>#include <iostream>#include <limits>#include <list>#include <map>#include <numeric>#include <queue>#include <random>#include <set>#include <sstream>#include <stack>#include <string>#include <tuple>#include <type_traits>#include <unordered_map>#include <unordered_set>#include <utility>#include <vector>using namespace std;using lint = long long;using pint = pair<int, int>;using plint = pair<lint, lint>;struct fast_ios { fast_ios(){ cin.tie(nullptr), ios::sync_with_stdio(false), cout << fixed << setprecision(20); }; } fast_ios_;#define ALL(x) (x).begin(), (x).end()#define FOR(i, begin, end) for(int i=(begin),i##_end_=(end);i<i##_end_;i++)#define IFOR(i, begin, end) for(int i=(end)-1,i##_begin_=(begin);i>=i##_begin_;i--)#define REP(i, n) FOR(i,0,n)#define IREP(i, n) IFOR(i,0,n)template <typename T, typename V>void ndarray(vector<T>& vec, const V& val, int len) { vec.assign(len, val); }template <typename T, typename V, typename... Args> void ndarray(vector<T>& vec, const V& val, int len, Args... args) { vec.resize(len), for_each(begin(vec), end(vec), [&](T& v) { ndarray(v, val, args...); }); }template <typename T> bool chmax(T &m, const T q) { return m < q ? (m = q, true) : false; }template <typename T> bool chmin(T &m, const T q) { return m > q ? (m = q, true) : false; }int floor_lg(long long x) { return x <= 0 ? -1 : 63 - __builtin_clzll(x); }template <typename T1, typename T2> pair<T1, T2> operator+(const pair<T1, T2> &l, const pair<T1, T2> &r) { return make_pair(l.first + r.first, l.second + r.second); }template <typename T1, typename T2> pair<T1, T2> operator-(const pair<T1, T2> &l, const pair<T1, T2> &r) { return make_pair(l.first - r.first, l.second - r.second); }template <typename T> vector<T> sort_unique(vector<T> vec) { sort(vec.begin(), vec.end()), vec.erase(unique(vec.begin(), vec.end()), vec.end());return vec; }template <typename T> int arglb(const std::vector<T> &v, const T &x) { return std::distance(v.begin(), std::lower_bound(v.begin(), v.end(), x)); }template <typename T> int argub(const std::vector<T> &v, const T &x) { return std::distance(v.begin(), std::upper_bound(v.begin(), v.end(), x)); }template <typename T> istream &operator>>(istream &is, vector<T> &vec) { for (auto &v : vec) is >> v; return is; }template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec) { os << '['; for (auto v : vec) os << v << ','; os << ']'; return os; }template <typename T, size_t sz> ostream &operator<<(ostream &os, const array<T, sz> &arr) { os << '['; for (auto v : arr) os << v << ','; os << ']';return os; }#if __cplusplus >= 201703Ltemplate <typename... T> istream &operator>>(istream &is, tuple<T...> &tpl) { std::apply([&is](auto &&... args) { ((is >> args), ...);}, tpl); returnis; }template <typename... T> ostream &operator<<(ostream &os, const tuple<T...> &tpl) { os << '('; std::apply([&os](auto &&... args) { ((os << args << ','), ...);}, tpl); return os << ')'; }#endiftemplate <typename T> ostream &operator<<(ostream &os, const deque<T> &vec) { os << "deq["; for (auto v : vec) os << v << ','; os << ']'; return os;}template <typename T> ostream &operator<<(ostream &os, const set<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }template <typename T, typename TH> ostream &operator<<(ostream &os, const unordered_set<T, TH> &vec) { os << '{'; for (auto v : vec) os << v << ',';os << '}'; return os; }template <typename T> ostream &operator<<(ostream &os, const multiset<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os;}template <typename T> ostream &operator<<(ostream &os, const unordered_multiset<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}';return os; }template <typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &pa) { os << '(' << pa.first << ',' << pa.second << ')';return os; }template <typename TK, typename TV> ostream &operator<<(ostream &os, const map<TK, TV> &mp) { os << '{'; for (auto v : mp) os << v.first << "=>" << v.second << ','; os << '}'; return os; }template <typename TK, typename TV, typename TH> ostream &operator<<(ostream &os, const unordered_map<TK, TV, TH> &mp) { os << '{'; for (auto v : mp)os << v.first << "=>" << v.second << ','; os << '}'; return os; }#ifdef HITONANODE_LOCALconst string COLOR_RESET = "\033[0m", BRIGHT_GREEN = "\033[1;32m", BRIGHT_RED = "\033[1;31m", BRIGHT_CYAN = "\033[1;36m", NORMAL_CROSSED = "\033[0;9;37m", RED_BACKGROUND = "\033[1;41m", NORMAL_FAINT = "\033[0;2m";#define dbg(x) cerr << BRIGHT_CYAN << #x << COLOR_RESET << " = " << (x) << NORMAL_FAINT << " (L" << __LINE__ << ") " << __FILE__ << COLOR_RESET <<endl#define dbgif(cond, x) ((cond) ? cerr << BRIGHT_CYAN << #x << COLOR_RESET << " = " << (x) << NORMAL_FAINT << " (L" << __LINE__ << ") " << __FILE__ <<COLOR_RESET << endl : cerr)#else#define dbg(x) (x)#define dbgif(cond, x) 0#endifvoid bad() {puts("-1");exit(0);}template <typename T, T INF = std::numeric_limits<T>::max() / 2, int INVALID = -1> struct ShortestPath {int V, E;bool single_positive_weight;T wmin, wmax;std::vector<std::vector<std::pair<int, T>>> to;ShortestPath(int V = 0) : V(V), E(0), single_positive_weight(true), wmin(0), wmax(0), to(V) {}void add_edge(int s, int t, T w) {assert(0 <= s and s < V);assert(0 <= t and t < V);to[s].emplace_back(t, w);E++;if (w > 0 and wmax > 0 and wmax != w) single_positive_weight = false;wmin = std::min(wmin, w);wmax = std::max(wmax, w);}std::vector<T> dist;std::vector<int> prev;// Dijkstra algorithm// Complexity: O(E log E)void Dijkstra(int s) {assert(0 <= s and s < V);dist.assign(V, INF);dist[s] = 0;prev.assign(V, INVALID);using P = std::pair<T, int>;std::priority_queue<P, std::vector<P>, std::greater<P>> pq;pq.emplace(0, s);while (!pq.empty()) {T d;int v;std::tie(d, v) = pq.top();pq.pop();if (dist[v] < d) continue;for (auto nx : to[v]) {T dnx = d + nx.second;if (dist[nx.first] > dnx) {dist[nx.first] = dnx, prev[nx.first] = v;pq.emplace(dnx, nx.first);}}}}// Dijkstra algorithm, O(V^2 + E)void DijkstraVquad(int s) {assert(0 <= s and s < V);dist.assign(V, INF);dist[s] = 0;prev.assign(V, INVALID);std::vector<char> fixed(V, false);while (true) {int r = INVALID;T dr = INF;for (int i = 0; i < V; i++) {if (!fixed[i] and dist[i] < dr) r = i, dr = dist[i];}if (r == INVALID) break;fixed[r] = true;int nxt;T dx;for (auto p : to[r]) {std::tie(nxt, dx) = p;if (dist[nxt] > dist[r] + dx) dist[nxt] = dist[r] + dx, prev[nxt] = r;}}}// Bellman-Ford algorithm// Complexity: O(VE)bool BellmanFord(int s, int nb_loop) {assert(0 <= s and s < V);dist.assign(V, INF), prev.assign(V, INVALID);dist[s] = 0;for (int l = 0; l < nb_loop; l++) {bool upd = false;for (int v = 0; v < V; v++) {if (dist[v] == INF) continue;for (auto nx : to[v]) {T dnx = dist[v] + nx.second;if (dist[nx.first] > dnx) dist[nx.first] = dnx, prev[nx.first] = v, upd = true;}}if (!upd) return true;}return false;}// Bellman-ford algorithm using queue (deque)// Complexity: O(VE)// Requirement: no negative loopvoid SPFA(int s) {assert(0 <= s and s < V);dist.assign(V, INF);prev.assign(V, INVALID);std::deque<int> q;std::vector<char> in_queue(V);dist[s] = 0;q.push_back(s), in_queue[s] = 1;while (!q.empty()) {int now = q.front();q.pop_front(), in_queue[now] = 0;for (auto nx : to[now]) {T dnx = dist[now] + nx.second;int nxt = nx.first;if (dist[nxt] > dnx) {dist[nxt] = dnx;if (!in_queue[nxt]) {if (q.size() and dnx < dist[q.front()]) { // Small label first optimizationq.push_front(nxt);} else {q.push_back(nxt);}prev[nxt] = now, in_queue[nxt] = 1;}}}}}void ZeroOneBFS(int s) {assert(0 <= s and s < V);dist.assign(V, INF), prev.assign(V, INVALID);dist[s] = 0;std::deque<int> que;que.push_back(s);while (!que.empty()) {int v = que.front();que.pop_front();for (auto nx : to[v]) {T dnx = dist[v] + nx.second;if (dist[nx.first] > dnx) {dist[nx.first] = dnx, prev[nx.first] = v;if (nx.second) {que.push_back(nx.first);} else {que.push_front(nx.first);}}}}}// Retrieve a sequence of vertex ids that represents shortest path [s, ..., goal]// If not reachable to goal, return {}std::vector<int> retrieve_path(int goal) const {assert(int(prev.size()) == V);assert(0 <= goal and goal < V);if (dist[goal] == INF) return {};std::vector<int> ret{goal};while (prev[goal] != INVALID) {goal = prev[goal];ret.push_back(goal);}std::reverse(ret.begin(), ret.end());return ret;}void solve(int s) {if (wmin >= 0) {if (single_positive_weight) {ZeroOneBFS(s);} else {if ((long long)V * V < (E << 4)) {DijkstraVquad(s);} else {Dijkstra(s);}}} else {BellmanFord(s, V);}}// Warshall-Floyd algorithm// Complexity: O(E + V^3)std::vector<std::vector<T>> dist2d;void WarshallFloyd() {dist2d.assign(V, std::vector<T>(V, INF));for (int i = 0; i < V; i++) {dist2d[i][i] = 0;for (auto p : to[i]) dist2d[i][p.first] = std::min(dist2d[i][p.first], p.second);}for (int k = 0; k < V; k++) {for (int i = 0; i < V; i++) {if (dist2d[i][k] == INF) continue;for (int j = 0; j < V; j++) {if (dist2d[k][j] == INF) continue;dist2d[i][j] = std::min(dist2d[i][j], dist2d[i][k] + dist2d[k][j]);}}}}void dump_graphviz(std::string filename = "shortest_path") const {std::ofstream ss(filename + ".DOT");ss << "digraph{\n";for (int i = 0; i < V; i++) {for (const auto &e : to[i]) ss << i << "->" << e.first << "[label=" << e.second << "];\n";}ss << "}\n";ss.close();return;}};int main() {int N, M;cin >> N >> M;vector<vector<tuple<int, int, char>>> to(N);set<char> sc;vector<tuple<int, int, char>> edges;ShortestPath<int> graph(N);REP(e, M) {int a, b;char c;cin >> a >> b >> c;sc.insert(c);a--, b--;to[a].emplace_back(b, e, c);to[b].emplace_back(a, e, c);edges.emplace_back(a, b, c);graph.add_edge(a, b, 1);graph.add_edge(b, a, 1);}if (sc.size() == 1) bad();const auto c0 = get<2>(to[0][0]);int e1, a1, b1;char c1;REP(e, M) {auto [a, b, c] = edges[e];if (c != c0) {e1 = e;a1 = a, b1 = b;c1 = c;}}graph.solve(0);auto p01 = graph.retrieve_path(a1);graph.solve(b1);auto pbN = graph.retrieve_path(N - 1);auto ret_e = [&](vector<int> vpath) {vector<int> ret;string retc;FOR(i, 1, vpath.size()) {for (auto [j, e, c] : to[vpath[i - 1]]) {if (j == vpath[i]) {ret.push_back(e);retc += c;break;}}}return make_pair(ret, retc);};auto [es1, S1] = ret_e(p01);auto [es2, S2] = ret_e(pbN);vector<int> seq = es1;seq.push_back(e1);dbg(seq);seq.insert(seq.end(), es2.begin(), es2.end());auto S = S1 + c1 + S2;auto Srev = S;reverse(ALL(Srev));if (S == Srev) {int e0 = get<1>(to[0][0]);REP(t, 2) seq.insert(seq.begin(), e0);}cout << seq.size() << '\n';for (auto x : seq) cout << x + 1 << '\n';}