結果

問題 No.3291 K-step Navigation
コンテスト
ユーザー Katu2ou
提出日時 2025-10-03 22:23:06
言語 C++23
(gcc 13.3.0 + boost 1.87.0)
結果
WA  
実行時間 -
コード長 7,702 bytes
コンパイル時間 3,235 ms
コンパイル使用メモリ 288,636 KB
実行使用メモリ 7,716 KB
最終ジャッジ日時 2025-10-03 22:23:15
合計ジャッジ時間 4,493 ms
ジャッジサーバーID
（参考情報） 		judge3 / judge4
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 2
other AC * 45 WA * 5
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 # 

//#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;

#define rep2(i, m, n) for (int i = (m); i < (n); ++i)
#define rep(i, n) rep2(i, 0, n)
#define drep2(i, m, n) for (int i = (m)-1; i >= (n); --i)
#define drep(i, n) drep2(i, n, 0)
#define all(...) std::begin(__VA_ARGS__), std::end(__VA_ARGS__)
#define rall(...) std::rbegin(__VA_ARGS__), std::rend(__VA_ARGS__)
#define CLR(a, b) memset((a), (b), sizeof(a))
#define DUMP(x) cout << #x << " = " << (x) << endl;
#define INF (long long)1001001001001001001
#define inf 1001001000
#define MOD 998244353
#define MOD1 1000000007
#define PI 3.14159265358979
#define epsilon 1e-12
#define fcout cout << fixed << setprecision(12)
#define MP make_pair
#define PB push_back
#define fi first
#define se second
#define ERASE(x) x.erase(unique(x.begin(),x.end()),x.end())

using ll = long long;
using ld = long double;
using vi = vector<int>;
using vl = vector<long long>;
using vs = vector<string>;
using vd = vector<double>;
using vld = vector<long double>;
using vb = vector<bool>;
using vpii = vector<pair<int, int>>;
using vpll = vector<pair<long long, long long>>;
using vvi = vector<vector<int>>;
using vvl = vector<vector<long long>>;
using vvd = vector<vector<double>>;
using vvld = vector<vector<long double>>;
using vvb = vector<vector<bool>>;
using vvpii = vector<vector<pair<int,int>>>;
using vvpll = vector<vector<pair<long long,long long>>>;
using vvvi = vector<vector<vector<int>>>;
using vvvl = vector<vector<vector<long long>>>;
using pii = pair<int, int>;
using pll = pair<long long, long long>;
using LL = __int128_t;

ll gcd(ll x, ll y) {if (x == 0) return y;	return gcd(y%x, x);} 
ll lcm(ll x, ll y) { __int128_t xx,yy; xx=x; yy=y; __int128_t ans=xx * yy / gcd(x, y); ll ans2=ans; return ans2; }
template<typename T>
T POW(T x, ll n){T ret=1;	while(n>0){		if(n&1) ret=ret*x;		x=x*x;		n>>=1;	}	return ret;}
template<typename T>
T modpow(T a, ll n, T p) {	if(n==0) return (T)1;  if (n == 1) return a % p;  if (n % 2 == 1) return (a * modpow(a, n - 1, p)) % p;  T t = modpow(a, n / 2, p);  return (t * t) % p;}
template<typename T>
T modinv(T a, T m) {	if(m==0)return (T)1;	T b = m, u = 1, v = 0;	while (b) {		T t = a / b;		a -= t * b; swap(a, b);		u -= t * v; swap(u, v);	}	u %= m;	if (u < 0) u += m;	return u;}
ll REM(ll a, ll b){ return (a % b + b) % b;}
ll QUO(ll a, ll b){ return (a - REM(a, b)) / b;}
/*
random_device rd;
mt19937 gen(rd());
uniform_int_distribution<> dist1(1, 100); [1,100]
int random_value = dist1(gen);
*/
/*
auto start = chrono::steady_clock::now(); //時間計測の開始
auto now = std::chrono::steady_clock::now(); //現在時刻と開始時刻の差を測定
double elapsed = std::chrono::duration<double>(now - start).count(); //時間をdouble型で取得
*/
/*
const int MAXCOMB=510000;
std::vector<mint> FAC(MAXCOMB), FINV(MAXCOMB), INV(MAXCOMB);
void COMinit() {FAC[0] = FAC[1] = 1;FINV[0] = FINV[1] = 1;INV[1] = 1;for (int i = 2; i < MAXCOMB; i++) {FAC[i] = FAC[i - 1] * i;INV[i] = mint(0) - INV[mint::mod() % i] * (mint::mod() / i);FINV[i] = FINV[i - 1] * INV[i];}}
mint COM(int n, int k) {if (n < k) return 0;if (n < 0 || k < 0) return 0;return FAC[n] * FINV[k] * FINV[n - k];}
*/

template <typename T> inline bool chmax(T &a, T b) { return ((a < b) ? (a = b, true) : (false));}
template <typename T> inline bool chmin(T &a, T b) { return ((a > b) ? (a = b, true) : (false));}
template <class T> T BS(vector<T> &vec, T key) {return lower_bound(vec.begin(), vec.end(), key) - vec.begin();}
template<class T> pair<T,T> RangeBS(vector<T> &vec, T lowv, T highv){auto itr_l = lower_bound(vec.begin(), vec.end(), lowv); auto itr_r = upper_bound(vec.begin(), vec.end(), highv); return make_pair(distance(vec.begin(), itr_l), distance(vec.begin(), itr_r)-1);}
void fail() { cout << "-1\n"; exit(0); } void no() { cout << "No\n"; exit(0); } void yes() { cout << "Yes\n"; exit(0); }
int dx[] = { 1,0,-1,0,1,1,-1,-1 }; int dy[] = { 0,1,0,-1,1,-1,1,-1};
bool range_in(int i, int j, int h, int w){ if(i<0 || j<0 || i>=h || j>=w) return false; return true;} 
int bitcount(int n){n=(n&0x55555555)+(n>>1&0x55555555); n=(n&0x33333333)+(n>>2&0x33333333); n=(n&0x0f0f0f0f)+(n>>4&0x0f0f0f0f); n=(n&0x00ff00ff)+(n>>8&0x00ff00ff); n=(n&0x0000ffff)+(n>>16&0x0000ffff); return n;}

template<typename T>
struct Edge{
    int from, to, index;
    T cost;
    Edge() : from(-1), to(-1), index(-1), cost(0) {}
    Edge(int _to) : from(-1), to(_to), index(-1), cost(0) {}
    Edge(int _to, T _cost) : from(-1), to(_to), index(-1), cost(_cost) {}
    Edge(int _from, int _to, int _index) : from(_from), to(_to), index(_index), cost(0) {}
    Edge(int _from, int _to, int _index, T _cost) 
        : from(_from), to(_to), index(_index), cost(_cost) {}
    bool operator<(const Edge<T>& other) const {
        return cost < other.cost; 
    }
    Edge &operator=(const int &x) {
        to = x;
        return *this;
    }
    operator int() const { return to; }
};
using Graph = vector<vector<int>>; 
template <typename T>
using WGraph = vector<vector<Edge<T>>>; 

/////////////////////////////////////////////////////////////////////////////////////////

class UnionFind
{
public:
	UnionFind() = default;
	explicit UnionFind(size_t n)
		: m_parentsOrSize(n, -1) {}
	int find(int i)
	{	if (m_parentsOrSize[i] < 0) return i;
		return (m_parentsOrSize[i] = find(m_parentsOrSize[i]));}
	void merge(int a, int b)
	{	a = find(a);
		b = find(b);
		if (a != b){
			if (-m_parentsOrSize[a] < -m_parentsOrSize[b]) std::swap(a, b);
			m_parentsOrSize[a] += m_parentsOrSize[b];
			m_parentsOrSize[b] = a;
		}
	}
	bool connected(int a, int b)
	{	return (find(a) == find(b));}
	int size(int i)
	{	return -m_parentsOrSize[find(i)];}
private:
	std::vector<int> m_parentsOrSize;
};

void solve(){
    ll n, m, k, s, t;
    cin >> n >> m >> k >> s >> t;
    s--;
    t--;
    UnionFind uf(n);
    vvi G(n);
    rep(i, m) {
        int a, b;
        cin>>a>>b;
        a--;
        b--;
        uf.merge(a, b);
        G[a].PB(b);
        G[b].PB(a);
    }
    if(uf.size(s)==2 && uf.connected(s,t)){
        if(k==2){
            cout<<"No"<<endl;
            return;
        }
        if(k%2==1){
            cout << "Yes" << endl;
            return;
        }
        vi seen(n);
        vi dist(n,-1);
        int val = inf;
        auto dfs = [&](auto&& dfs, int v, int prev) -> void {
            seen[v] = 1;
            for(int to:G[v]){
                if(to==prev)
                    continue;
                if(seen[to]==1 && dist[to]!=-1){
                    if(abs(dist[to]-(dist[v]+1))%2==1){
                        //cout << dist[to] << " " << dist[v] << endl;
                        chmin(val, abs(dist[to] - (dist[v] + 1)));
                    }
                    continue;
                }
                if(seen[to]==1)
                    continue;
                dist[to] = dist[v] + 1;
                dfs(dfs, to, v);
                dist[to] = -1;
            }
        };
        rep(i,n){
            // rep(j, n) seen[j] = 0;
            // rep(j, n) dist[j] = -1;
            if (seen[i] == 0) {
                dist[i] = 0;
                dfs(dfs, i, -1);
            }
        }
        //cout << val << endl;
        if (k >= 3 + val) {
            cout << "Yes" << endl;
        } else
            cout << "No" << endl;
        return;
    }
    if(uf.size(s)!=1 || uf.size(t)!=1){
        cout << "Yes" << endl;
    }
    else{
        if(k%2==1){
            cout << "Yes" << endl;
        }
        else
            cout << "No" << endl;
    }
}

signed main(){
	cin.tie(0);
	ios::sync_with_stdio(0);
	cout<<fixed<<setprecision(20);
	int TT; TT = 1; //cin >> TT;
	while(TT--) solve();
}
0