#pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; //#define int long long typedef long long ll; typedef unsigned long long ul; typedef unsigned int ui; constexpr ll mod = 998244353; //constexpr ll mod = 1000000007; const ll INF = mod * mod; typedef pairP; #define rep(i,n) for(int i=0;i=0;i--) #define Rep(i,sta,n) for(int i=sta;i=1;i--) #define Rep1(i,sta,n) for(int i=sta;i<=n;i++) #define all(v) (v).begin(),(v).end() typedef pair LP; template void chmin(T& a, T b) { a = min(a, b); } template void chmax(T& a, T b) { a = max(a, b); } template void cinarray(vector& v) { rep(i, v.size())cin >> v[i]; } template void coutarray(vector& v) { rep(i, v.size()) { if (i > 0)cout << " "; cout << v[i]; } cout << "\n"; } ll mod_pow(ll x, ll n, ll m = mod) { if (n < 0) { ll res = mod_pow(x, -n, m); return mod_pow(res, m - 2, m); } if (abs(x) >= m)x %= m; if (x < 0)x += m; //if (x == 0)return 0; ll res = 1; while (n) { if (n & 1)res = res * x % m; x = x * x % m; n >>= 1; } return res; } struct modint { int n; modint() :n(0) { ; } modint(ll m) { if (m < 0 || mod <= m) { m %= mod; if (m < 0)m += mod; } n = m; } operator int() { return n; } }; bool operator==(modint a, modint b) { return a.n == b.n; } bool operator<(modint a, modint b) { return a.n < b.n; } modint operator+=(modint& a, modint b) { a.n += b.n; if (a.n >= mod)a.n -= mod; return a; } modint operator-=(modint& a, modint b) { a.n -= b.n; if (a.n < 0)a.n += mod; return a; } modint operator*=(modint& a, modint b) { a.n = ((ll)a.n * b.n) % mod; return a; } modint operator+(modint a, modint b) { return a += b; } modint operator-(modint a, modint b) { return a -= b; } modint operator*(modint a, modint b) { return a *= b; } modint operator^(modint a, ll n) { if (n == 0)return modint(1); modint res = (a * a) ^ (n / 2); if (n % 2)res = res * a; return res; } ll inv(ll a, ll p) { return (a == 1 ? 1 : (1 - p * inv(p % a, a)) / a + p); } modint operator/(modint a, modint b) { return a * modint(inv(b, mod)); } modint operator/=(modint& a, modint b) { a = a / b; return a; } const int max_n = 1 << 20; modint fact[max_n], factinv[max_n]; void init_f() { fact[0] = modint(1); for (int i = 0; i < max_n - 1; i++) { fact[i + 1] = fact[i] * modint(i + 1); } factinv[max_n - 1] = modint(1) / fact[max_n - 1]; for (int i = max_n - 2; i >= 0; i--) { factinv[i] = factinv[i + 1] * modint(i + 1); } } modint comb(int a, int b) { if (a < 0 || b < 0 || a < b)return 0; return fact[a] * factinv[b] * factinv[a - b]; } modint combP(int a, int b) { if (a < 0 || b < 0 || a < b)return 0; return fact[a] * factinv[a - b]; } ll gcd(ll a, ll b) { a = abs(a); b = abs(b); if (a < b)swap(a, b); while (b) { ll r = a % b; a = b; b = r; } return a; } typedef long double ld; typedef pair LDP; const ld eps = 1e-8; const ld pi = acosl(-1.0); template void addv(vector& v, int loc, T val) { if (loc >= v.size())v.resize(loc + 1, 0); v[loc] += val; } /*const int mn = 100005; bool isp[mn]; vector ps; void init() { fill(isp + 2, isp + mn, true); for (int i = 2; i < mn; i++) { if (!isp[i])continue; ps.push_back(i); for (int j = 2 * i; j < mn; j += i) { isp[j] = false; } } }*/ //[,val) template auto prev_itr(set& st, T val) { auto res = st.lower_bound(val); if (res == st.begin())return st.end(); res--; return res; } //[val,) template auto next_itr(set& st, T val) { auto res = st.lower_bound(val); return res; } using mP = pair; mP operator+(mP a, mP b) { return { a.first + b.first,a.second + b.second }; } mP operator+=(mP& a, mP b) { a = a + b; return a; } mP operator-(mP a, mP b) { return { a.first - b.first,a.second - b.second }; } mP operator-=(mP& a, mP b) { a = a - b; return a; } mt19937 mt(time(0)); const string drul = "DRUL"; string senw = "SENW"; //DRUL,or SENW int dx[4] = { 1,0,-1,0 }; int dy[4] = { 0,1,0,-1 }; //----------------------------------------- struct LowLink { private: vector> G; vector used, ord, low; vector art; vector

bridge; //make graph with bridge vector> fG; vector> ori; vector trans; public: LowLink(int n) { G.resize(n); used.resize(n, 0); ord.resize(n, 0); low.resize(n, 0); } void add_edge(int a, int b) { if (a == b)return; G[a].push_back(b); G[b].push_back(a); } int dfs(int id, int k, int par) { used[id] = true; ord[id] = k++; low[id] = ord[id]; bool is_art = false; int cnt = 0; for (auto&& to : G[id]) { if (!used[to]) { ++cnt; k = dfs(to, k, id); low[id] = min(low[id], low[to]); if (~par && low[to] >= ord[id])is_art = true; if (ord[id] < low[to])bridge.emplace_back(minmax(id, to)); } else if (to != par) { low[id] = min(low[id], ord[to]); } } if (par == -1 && cnt > 1)is_art = true; if (is_art)art.push_back(id); return k; } void complete() { int k = 0; rep(i, G.size()) { if (!used[i]) { k = dfs(i, k, -1); } } //if there is mutiple edge map era; rep(i, G.size()) { sort(all(G[i])); rep1(j, (int)G[i].size() - 1) { if (G[i][j] == G[i][j - 1]) { era[minmax(i, G[i][j])] = true; } } } vector

cop = bridge; bridge.clear(); for (P p : cop) { if (era[p])continue; bridge.push_back(p); } } vector

bs() { return bridge; } void makegraph_bridge() { map pused; for (P p : bridge) { pused[minmax(p.first, p.second)] = true; } fill(all(used), false); int tmp = 0; int n = G.size(); trans.resize(n); rep(i, n) { if (used[i])continue; vector ids, tos; queue q; q.push(i); used[i] = true; while (!q.empty()) { int cur = q.front(); q.pop(); ids.push_back(cur); for (int to : G[cur]) { if (pused[minmax(cur, to)]) { tos.push_back(to); continue; } if (used[to])continue; used[to] = true; q.push(to); } } ori.push_back(ids); fG.push_back(tos); for (int id : ids) { trans[id] = tmp; } tmp++; } rep(i, tmp) { for (int& to : fG[i]) { to = trans[to]; } } } }; struct uf { private: vector par, ran; public: uf(int n) { par.resize(n, 0); ran.resize(n, 0); rep(i, n) { par[i] = i; } } int find(int x) { if (par[x] == x)return x; else return par[x] = find(par[x]); } void unite(int x, int y) { x = find(x), y = find(y); if (x == y)return; if (ran[x] < ran[y]) { par[x] = y; } else { par[y] = x; if (ran[x] == ran[y])ran[x]++; } } bool same(int x, int y) { return find(x) == find(y); } }; void solve() { int n, m, q; cin >> n >> m >> q; LowLink lt(n); rep(i, m) { int a, b; cin >> a >> b; a--; b--; lt.add_edge(a, b); } lt.complete(); vector

bs = lt.bs(); uf u(n); for (auto p : bs) { u.unite(p.first, p.second); } rep(i, q) { int x, y; cin >> x >> y; x--; y--; if (u.same(x, y)) { cout << "Yes\n"; } else { cout << "No\n"; } } } signed main() { ios::sync_with_stdio(false); cin.tie(0); //cout << fixed << setprecision(10); //init_f(); //init(); //while(true) //expr(); //int t; cin >> t; rep(i, t) solve(); return 0; }