This documentation is automatically generated by online-judge-tools/verification-helper
// competitive-verifier: PROBLEM http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=2405
#include "../../template/template.hpp"
#include "../../math/combinatorics/montgomery-mod-int.hpp"
#include "../../graph/others/tree-decomposition-width-2.hpp"
constexpr int MOD = 1000003;
using Mint = modint< MOD >;
int main() {
int N, M;
while(cin >> N >> M, N) {
TreeDecompositionWidth2 td(N);
set< pair< int, int > > edges;
for(int i = 0; i < N; i++) {
td.add_edge(i, (i + 1) % N);
edges.emplace(minmax(i, (i + 1) % N));
}
for(int i = 0; i < M; i++) {
int a, b;
cin >> a >> b;
--a, --b;
td.add_edge(a, b);
edges.emplace(minmax(a, b));
}
if(N % 2) {
cout << 0 << endl;
continue;
}
auto t = td.build();
to_nice(t);
vector< vector< Mint > > dps(t.size());
vector< int > buff(N), buff2(N, -1);
MFP([&](auto rec, int idx) -> void {
auto &ch = t[idx].child;
auto &bag = t[idx].bag;
for(auto &to : ch) rec(to);
vector< Mint > dp(1 << bag.size());
if(ch.empty()) { // leaf
dp[0] = 1;
} else if(ch.size() == 2) { // join
for(int i = 0; i < dp.size(); i++) {
for(int j = 0; j < dp.size(); j++) {
if((i & j) == 0) dp[i | j] += dps[ch[0]][i] * dps[ch[1]][j];
}
}
} else {
auto &ch_bag = t[ch[0]].bag;
auto &ch_dp = dps[ch[0]];
for(int i = 0; i < bag.size(); i++) {
buff[bag[i]] = 1 << i;
buff2[bag[i]] = idx;
}
if(ch_bag.size() + 1 == bag.size()) { // introduce
for(int i = 0; i < ch_dp.size(); i++) {
int bit = 0;
for(int j = 0; j < ch_bag.size(); j++) {
if((i >> j) & 1) bit |= buff[ch_bag[j]];
}
dp[bit] = ch_dp[i];
}
} else { // forget
int v = -1;
for(int i = 0; i < ch_bag.size(); i++) {
if(buff2[ch_bag[i]] != idx) v = ch_bag[i];
}
vector< int > ok_match(bag.size());
for(int i = 0; i < bag.size(); i++) {
ok_match[i] = edges.count(minmax(bag[i], v));
}
for(int i = 0; i < ch_dp.size(); i++) {
int bit = 0;
bool v_use = false;
for(int j = 0; j < ch_bag.size(); j++) {
if((i >> j) & 1) {
if(v != ch_bag[j]) bit |= buff[ch_bag[j]];
} else {
if(v == ch_bag[j]) v_use = true;
}
}
if(v_use) {
for(int j = 0; j < bag.size(); j++) {
if((bit >> j) & 1) continue;
if(ok_match[j]) dp[bit | (1 << j)] += ch_dp[i];
}
} else {
dp[bit] += ch_dp[i];
}
}
}
}
dps[idx].swap(dp);
})(0);
auto &dp = dps[0];
cout << dp.back() << endl;
}
}
#line 1 "test/verify/aoj-2405.test.cpp"
// competitive-verifier: PROBLEM http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=2405
#line 1 "template/template.hpp"
#include<bits/stdc++.h>
using namespace std;
using int64 = long long;
const int64 infll = (1LL << 62) - 1;
const int inf = (1 << 30) - 1;
struct IoSetup {
IoSetup() {
cin.tie(nullptr);
ios::sync_with_stdio(false);
cout << fixed << setprecision(10);
cerr << fixed << setprecision(10);
}
} iosetup;
template< typename T1, typename T2 >
ostream &operator<<(ostream &os, const pair< T1, T2 >& p) {
os << p.first << " " << p.second;
return os;
}
template< typename T1, typename T2 >
istream &operator>>(istream &is, pair< T1, T2 > &p) {
is >> p.first >> p.second;
return is;
}
template< typename T >
ostream &operator<<(ostream &os, const vector< T > &v) {
for(int i = 0; i < (int) v.size(); i++) {
os << v[i] << (i + 1 != v.size() ? " " : "");
}
return os;
}
template< typename T >
istream &operator>>(istream &is, vector< T > &v) {
for(T &in : v) is >> in;
return is;
}
template< typename T1, typename T2 >
inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }
template< typename T1, typename T2 >
inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); }
template< typename T = int64 >
vector< T > make_v(size_t a) {
return vector< T >(a);
}
template< typename T, typename... Ts >
auto make_v(size_t a, Ts... ts) {
return vector< decltype(make_v< T >(ts...)) >(a, make_v< T >(ts...));
}
template< typename T, typename V >
typename enable_if< is_class< T >::value == 0 >::type fill_v(T &t, const V &v) {
t = v;
}
template< typename T, typename V >
typename enable_if< is_class< T >::value != 0 >::type fill_v(T &t, const V &v) {
for(auto &e : t) fill_v(e, v);
}
template< typename F >
struct FixPoint : F {
explicit FixPoint(F &&f) : F(forward< F >(f)) {}
template< typename... Args >
decltype(auto) operator()(Args &&... args) const {
return F::operator()(*this, forward< Args >(args)...);
}
};
template< typename F >
inline decltype(auto) MFP(F &&f) {
return FixPoint< F >{forward< F >(f)};
}
#line 2 "math/combinatorics/montgomery-mod-int.hpp"
template< uint32_t mod_, bool fast = false >
struct MontgomeryModInt {
private:
using mint = MontgomeryModInt;
using i32 = int32_t;
using i64 = int64_t;
using u32 = uint32_t;
using u64 = uint64_t;
static constexpr u32 get_r() {
u32 ret = mod_;
for (i32 i = 0; i < 4; i++) ret *= 2 - mod_ * ret;
return ret;
}
static constexpr u32 r = get_r();
static constexpr u32 n2 = -u64(mod_) % mod_;
static_assert(r * mod_ == 1, "invalid, r * mod != 1");
static_assert(mod_ < (1 << 30), "invalid, mod >= 2 ^ 30");
static_assert((mod_ & 1) == 1, "invalid, mod % 2 == 0");
u32 x;
public:
MontgomeryModInt(): x{} {}
MontgomeryModInt(const i64 &a)
: x(reduce(u64(fast ? a : (a % mod() + mod())) * n2)) {}
static constexpr u32 reduce(const u64 &b) {
return u32(b >> 32) + mod() - u32((u64(u32(b) * r) * mod()) >> 32);
}
mint &operator+=(const mint &p) {
if (i32(x += p.x - 2 * mod()) < 0) x += 2 * mod();
return *this;
}
mint &operator-=(const mint &p) {
if (i32(x -= p.x) < 0) x += 2 * mod();
return *this;
}
mint &operator*=(const mint &p) {
x = reduce(u64(x) * p.x);
return *this;
}
mint &operator/=(const mint &p) {
*this *= p.inv();
return *this;
}
mint operator-() const { return mint() - *this; }
mint operator+(const mint &p) const { return mint(*this) += p; }
mint operator-(const mint &p) const { return mint(*this) -= p; }
mint operator*(const mint &p) const { return mint(*this) *= p; }
mint operator/(const mint &p) const { return mint(*this) /= p; }
bool operator==(const mint &p) const {
return (x >= mod() ? x - mod() : x) == (p.x >= mod() ? p.x - mod() : p.x);
}
bool operator!=(const mint &p) const {
return (x >= mod() ? x - mod() : x) != (p.x >= mod() ? p.x - mod() : p.x);
}
u32 val() const {
u32 ret = reduce(x);
return ret >= mod() ? ret - mod() : ret;
}
mint pow(u64 n) const {
mint ret(1), mul(*this);
while (n > 0) {
if (n & 1) ret *= mul;
mul *= mul;
n >>= 1;
}
return ret;
}
mint inv() const {
return pow(mod() - 2);
}
friend ostream &operator<<(ostream &os, const mint &p) {
return os << p.val();
}
friend istream &operator>>(istream &is, mint &a) {
i64 t;
is >> t;
a = mint(t);
return is;
}
static constexpr u32 mod() { return mod_; }
};
template< uint32_t mod >
using modint = MontgomeryModInt< mod >;
using modint998244353 = modint< 998244353 >;
using modint1000000007 = modint< 1000000007 >;
#line 5 "test/verify/aoj-2405.test.cpp"
#line 2 "graph/others/tree-decomposition-width-2.hpp"
/**
* @brief Tree Decomposition Width 2(木幅2の木分解)
* @see https://ei1333.hateblo.jp/entry/2020/02/12/150319
*
*/
struct DecompNode {
vector< int > bag, child;
DecompNode() = default;
};
struct TreeDecompositionWidth2 {
vector< vector< int > > g;
explicit TreeDecompositionWidth2(int V) : g(V) {}
void add_edge(int a, int b) {
g[a].emplace_back(b);
g[b].emplace_back(a);
}
vector< DecompNode > build() {
const int N = (int) g.size();
vector< int > used(N, -1), deg(N);
queue< int > que;
for(int i = 0; i < N; i++) {
deg[i] = (int) g[i].size();
if(deg[i] <= 2) que.emplace(i);
}
vector< set< int > > exists(N);
for(int i = 0; i < N; i++) {
for(auto &j : g[i]) {
if(i < j) exists[i].emplace(j);
}
}
vector< DecompNode > ret;
ret.emplace_back();
while(!que.empty()) {
int idx = que.front();
que.pop();
if(deg[idx] > 2 || used[idx] != -1) continue;
DecompNode r;
r.bag.emplace_back(idx);
int u = -1, v = -1;
for(auto &to : g[idx]) {
if(used[to] == -1) {
(u == -1 ? u : v) = to;
r.bag.emplace_back(to);
} else if(used[to] >= 0) {
r.child.emplace_back(used[to]);
used[to] = -2;
}
}
if(u == -1) {
} else if(v == -1) {
--deg[u];
} else {
if(u > v) swap(u, v);
if(!exists[u].count(v)) {
g[u].emplace_back(v);
g[v].emplace_back(u);
exists[u].emplace(v);
} else {
--deg[u];
--deg[v];
}
}
for(auto &to : g[idx]) {
if(deg[to] <= 2) que.emplace(to);
}
used[idx] = (int) ret.size();
deg[idx] = 0;
ret.emplace_back(r);
}
for(int i = 0; i < N; i++) {
if(deg[i] > 0) return {};
}
ret.front() = ret.back();
ret.pop_back();
return ret;
}
};
void to_nice(vector< DecompNode > &g, int root = 0) {
for(auto &p : g) {
sort(p.bag.begin(), p.bag.end());
}
stack< int > st;
st.emplace(root);
while(!st.empty()) {
int idx = st.top();
st.pop();
// join
while(g[idx].child.size() > 2) {
DecompNode r;
r.child.resize(2);
r.child[0] = g[idx].child.back();
g[idx].child.pop_back();
r.child[1] = g[idx].child.back();
g[idx].child.pop_back();
r.bag = g[idx].bag;
g[idx].child.emplace_back((int) g.size());
g.emplace_back(r);
}
if(g[idx].child.size() == 2) {
for(auto &ch : g[idx].child) {
if(g[ch].bag != g[idx].bag) {
DecompNode r;
r.child = {ch};
r.bag = g[idx].bag;
ch = (int) g.size();
g.emplace_back(r);
}
}
}
// introduce / forget
if(g[idx].child.size() == 1) {
int &ch = g[idx].child[0];
vector< int > latte, malta;
set_difference(g[idx].bag.begin(), g[idx].bag.end(),
g[ch].bag.begin(), g[ch].bag.end(),
back_inserter(latte));
set_difference(g[ch].bag.begin(), g[ch].bag.end(),
g[idx].bag.begin(), g[idx].bag.end(),
back_inserter(malta));
if(latte.size() + malta.size() > 1) {
DecompNode r;
r.child = {ch};
r.bag = g[idx].bag;
if(!latte.empty()) {
r.bag.erase(find(r.bag.begin(), r.bag.end(), latte.back()));
} else {
r.bag.emplace_back(malta.back());
}
ch = (int) g.size();
g.emplace_back(r);
}
}
// leaf
if(g[idx].child.empty()) {
if(g[idx].bag.size() > 1) {
DecompNode r;
r.bag = g[idx].bag;
r.bag.pop_back();
g[idx].child.emplace_back((int) g.size());
g.emplace_back(r);
}
}
for(auto &ch : g[idx].child) {
st.emplace(ch);
}
}
}
#line 7 "test/verify/aoj-2405.test.cpp"
constexpr int MOD = 1000003;
using Mint = modint< MOD >;
int main() {
int N, M;
while(cin >> N >> M, N) {
TreeDecompositionWidth2 td(N);
set< pair< int, int > > edges;
for(int i = 0; i < N; i++) {
td.add_edge(i, (i + 1) % N);
edges.emplace(minmax(i, (i + 1) % N));
}
for(int i = 0; i < M; i++) {
int a, b;
cin >> a >> b;
--a, --b;
td.add_edge(a, b);
edges.emplace(minmax(a, b));
}
if(N % 2) {
cout << 0 << endl;
continue;
}
auto t = td.build();
to_nice(t);
vector< vector< Mint > > dps(t.size());
vector< int > buff(N), buff2(N, -1);
MFP([&](auto rec, int idx) -> void {
auto &ch = t[idx].child;
auto &bag = t[idx].bag;
for(auto &to : ch) rec(to);
vector< Mint > dp(1 << bag.size());
if(ch.empty()) { // leaf
dp[0] = 1;
} else if(ch.size() == 2) { // join
for(int i = 0; i < dp.size(); i++) {
for(int j = 0; j < dp.size(); j++) {
if((i & j) == 0) dp[i | j] += dps[ch[0]][i] * dps[ch[1]][j];
}
}
} else {
auto &ch_bag = t[ch[0]].bag;
auto &ch_dp = dps[ch[0]];
for(int i = 0; i < bag.size(); i++) {
buff[bag[i]] = 1 << i;
buff2[bag[i]] = idx;
}
if(ch_bag.size() + 1 == bag.size()) { // introduce
for(int i = 0; i < ch_dp.size(); i++) {
int bit = 0;
for(int j = 0; j < ch_bag.size(); j++) {
if((i >> j) & 1) bit |= buff[ch_bag[j]];
}
dp[bit] = ch_dp[i];
}
} else { // forget
int v = -1;
for(int i = 0; i < ch_bag.size(); i++) {
if(buff2[ch_bag[i]] != idx) v = ch_bag[i];
}
vector< int > ok_match(bag.size());
for(int i = 0; i < bag.size(); i++) {
ok_match[i] = edges.count(minmax(bag[i], v));
}
for(int i = 0; i < ch_dp.size(); i++) {
int bit = 0;
bool v_use = false;
for(int j = 0; j < ch_bag.size(); j++) {
if((i >> j) & 1) {
if(v != ch_bag[j]) bit |= buff[ch_bag[j]];
} else {
if(v == ch_bag[j]) v_use = true;
}
}
if(v_use) {
for(int j = 0; j < bag.size(); j++) {
if((bit >> j) & 1) continue;
if(ok_match[j]) dp[bit | (1 << j)] += ch_dp[i];
}
} else {
dp[bit] += ch_dp[i];
}
}
}
}
dps[idx].swap(dp);
})(0);
auto &dp = dps[0];
cout << dp.back() << endl;
}
}
Env | Name | Status | Elapsed | Memory |
---|---|---|---|---|
g++ | testcase_00 | AC | 627 ms | 63 MB |
g++ | testcase_01 | AC | 633 ms | 63 MB |
g++ | testcase_02 | AC | 621 ms | 63 MB |
g++ | testcase_03 | AC | 634 ms | 64 MB |
clang++ | testcase_00 | AC | 624 ms | 66 MB |
clang++ | testcase_01 | AC | 612 ms | 66 MB |
clang++ | testcase_02 | AC | 610 ms | 64 MB |
clang++ | testcase_03 | AC | 617 ms | 65 MB |