#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; #define rep(i, n) for (int i = 0; i < n; i++) #define rep1(i, n) for (int i = 1; i < n + 1; i++) #define rev(i, n) for (int i = n - 1; i >= 0; i--) #define all(A) A.begin(), A.end() #define itr(A, l, r) A.begin() + l, A.begin() + r #define debug(var) cout << #var << " = " << var << endl; typedef long long ll; template ostream &operator<<(ostream &os, const pair &p) { os << "(" << p.first << "," << p.second << ")"; return os; } template istream &operator>>(istream &is, pair &p) { is >> p.first >> p.second; return is; } template ostream &operator<<(ostream &os, const vector &v) { for (int i = 0; i < (int)v.size(); i++) { os << v[i] << (i + 1 != (int)v.size() ? " " : ""); } return os; } template ostream &operator<<(ostream &os, const vector> &v) { for (int i = 0; i < (int)v.size(); i++) { os << v[i] << endl; } return os; } template ostream &operator<<(ostream &os, const vector>> &v) { for (int i = 0; i < (int)v.size(); i++) { os << "i = " << i << endl; os << v[i]; } return os; } template istream &operator>>(istream &is, vector &v) { for (T &in : v) is >> in; return is; } template ostream &operator<<(ostream &os, map &mp) { for (auto &[key, val] : mp) { os << key << ":" << val << " "; } cout << endl; return os; } template ostream &operator<<(ostream &os, set st) { auto itr = st.begin(); for (int i = 0; i < (int)st.size(); i++) { os << *itr << (i + 1 != (int)st.size() ? " " : ""); itr++; } return os; } template ostream &operator<<(ostream &os, multiset st) { auto itr = st.begin(); for (int i = 0; i < (int)st.size(); i++) { os << *itr << (i + 1 != (int)st.size() ? " " : ""); itr++; } return os; } template ostream &operator<<(ostream &os, queue q) { while (q.size()) { os << q.front() << " "; q.pop(); } return os; } template ostream &operator<<(ostream &os, deque q) { while (q.size()) { os << q.front() << " "; q.pop_front(); } return os; } template ostream &operator<<(ostream &os, stack st) { while (st.size()) { os << st.top() << " "; st.pop(); } return os; } template ostream &operator<<(ostream &os, priority_queue pq) { while (pq.size()) { os << pq.top() << " "; pq.pop(); } return os; } template ostream &operator<<(ostream &os, priority_queue, greater> mpq) { while (mpq.size()) { os << mpq.top() << " "; mpq.pop(); } return os; } struct UnionFind { vector par; UnionFind(int N) : par(N) { for (int i = 0; i < N; i++) par[i] = -1; } int root(int x) { if (par[x] < 0) return x; return par[x] = root(par[x]); } void unite(int x, int y) { int rx = root(x); int ry = root(y); if (same(x, y)) { return; } if (par[rx] > par[ry]) swap(rx, ry); par[rx] += par[ry]; par[ry] = rx; return; } bool same(int x, int y) { int rx = root(x); int ry = root(y); return rx == ry; } int size(int x) { return -par[root(x)]; } }; int main() { int n, q; cin >> n >> q; UnionFind uf(n); rep(i, n) { int p; cin >> p; p--; if (p == -2) { continue; } uf.unite(i, p); } while (q--) { int a, b; cin >> a >> b; a--; b--; if (uf.same(a, b)) { cout << "Yes" << endl; } else { cout << "No" << endl; } } }