#include using namespace std; #define rep(i, n) for (int i = 0; i < n; i++) #define rep2(i, x, n) for (int i = x; i <= n; i++) #define rep3(i, x, n) for (int i = x; i >= n; i--) #define each(e, v) for (auto &e : v) #define pb push_back #define eb emplace_back #define all(x) x.begin(), x.end() #define rall(x) x.rbegin(), x.rend() #define sz(x) (int)x.size() using ll = long long; using pii = pair; using pil = pair; using pli = pair; using pll = pair; template bool chmax(T &x, const T &y) { return (x < y) ? (x = y, true) : false; } template bool chmin(T &x, const T &y) { return (x > y) ? (x = y, true) : false; } template int flg(T x, int i) { return (x >> i) & 1; } template void print(const vector &v, T x = 0) { int n = v.size(); for (int i = 0; i < n; i++) cout << v[i] + x << (i == n - 1 ? '\n' : ' '); if (v.empty()) cout << '\n'; } template void printn(const vector &v, T x = 0) { int n = v.size(); for (int i = 0; i < n; i++) cout << v[i] + x << '\n'; } template int lb(const vector &v, T x) { return lower_bound(begin(v), end(v), x) - begin(v); } template int ub(const vector &v, T x) { return upper_bound(begin(v), end(v), x) - begin(v); } template void rearrange(vector &v) { sort(begin(v), end(v)); v.erase(unique(begin(v), end(v)), end(v)); } template vector id_sort(const vector &v, bool greater = false) { int n = v.size(); vector ret(n); iota(begin(ret), end(ret), 0); sort(begin(ret), end(ret), [&](int i, int j) { return greater ? v[i] > v[j] : v[i] < v[j]; }); return ret; } template pair operator+(const pair &p, const pair &q) { return make_pair(p.first + q.first, p.second + q.second); } template pair operator-(const pair &p, const pair &q) { return make_pair(p.first - q.first, p.second - q.second); } template istream &operator>>(istream &is, pair &p) { S a; T b; is >> a >> b; p = make_pair(a, b); return is; } template ostream &operator<<(ostream &os, const pair &p) { return os << p.first << ' ' << p.second; } struct io_setup { io_setup() { ios_base::sync_with_stdio(false); cin.tie(NULL); cout << fixed << setprecision(15); } } io_setup; const int inf = (1 << 30) - 1; const ll INF = (1LL << 60) - 1; const int MOD = 1000000007; // const int MOD = 998244353; template struct Binary_Indexed_Tree { vector bit; const int n; Binary_Indexed_Tree(const vector &v) : n((int)v.size()) { bit.resize(n + 1); copy(begin(v), end(v), begin(bit) + 1); for (int a = 2; a <= n; a <<= 1) { for (int b = a; b <= n; b += a) bit[b] += bit[b - a / 2]; } } Binary_Indexed_Tree(int n, const T &x) : n(n) { bit.resize(n + 1); vector v(n, x); copy(begin(v), end(v), begin(bit) + 1); for (int a = 2; a <= n; a <<= 1) { for (int b = a; b <= n; b += a) bit[b] += bit[b - a / 2]; } } void add(int i, const T &x) { for (i++; i <= n; i += (i & -i)) bit[i] += x; } void change(int i, const T &x) { add(i, x - query(i, i + 1)); } T sum(int i) const { T ret = 0; for (; i > 0; i -= (i & -i)) ret += bit[i]; return ret; } T query(int l, int r) const { return sum(r) - sum(l); } T operator[](int i) const { return query(i, i + 1); } int lower_bound(T x) const { int ret = 0; for (int k = 31 - __builtin_clz(n); k >= 0; k--) { if (ret + (1 << k) <= n && bit[ret + (1 << k)] < x) x -= bit[ret += (1 << k)]; } return ret; } int upper_bound(T x) const { int ret = 0; for (int k = 31 - __builtin_clz(n); k >= 0; k--) { if (ret + (1 << k) <= n && bit[ret + (1 << k)] <= x) x -= bit[ret += (1 << k)]; } return ret; } }; int main() { int N; cin >> N; vector P(N), Q(N); rep(i, N) { cin >> P[i]; P[i]--; Q[P[i]] = i; } auto memo = Q; Binary_Indexed_Tree bit(N, 0); vector S(N); rep(i, N) { S[i] = bit.query(0, Q[i]) & 1; bit.add(Q[i], 1); } vector R(N); iota(all(R), 0); // print(Q), print(S); rep(i, N - 1) { bool flip = false; if (S[i] == 1) { if (S[i + 1] == 0 && Q[i] < Q[i + 1]) { cout << "No\n"; return 0; } if (S[i + 1] == 1 && Q[i] > Q[i + 1]) { cout << "No\n"; return 0; } flip = true; } else if (S[i + 1] == 1 && Q[i] < Q[i + 1]) { flip = true; } if (flip) { swap(Q[i], Q[i + 1]); swap(R[i], R[i + 1]); swap(S[i], S[i + 1]); (Q[i] > Q[i + 1] ? S[i] : S[i + 1]) ^= 1; } // print(Q), print(S); } if (S[N - 1] == 1) { cout << "No\n"; return 0; } cout << "Yes\n"; Binary_Indexed_Tree bit2(N, 0); each(e, R) { cout << e + 1 << ' ' << bit2.query(0, memo[e]) + 1 << '\n'; bit2.add(memo[e], 1); } }