#define _USE_MATH_DEFINES #include using namespace std; #define FOR(i,m,n) for(int i=(m);i<(n);++i) #define REP(i,n) FOR(i,0,n) #define ALL(v) (v).begin(),(v).end() using ll = long long; constexpr int INF = 0x3f3f3f3f; constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL; constexpr double EPS = 1e-8; constexpr int MOD = 1000000007; // constexpr int MOD = 998244353; constexpr int DY4[]{1, 0, -1, 0}, DX4[]{0, -1, 0, 1}; constexpr int DY8[]{1, 1, 0, -1, -1, -1, 0, 1}; constexpr int DX8[]{0, -1, -1, -1, 0, 1, 1, 1}; template inline bool chmax(T& a, U b) { return a < b ? (a = b, true) : false; } template inline bool chmin(T& a, U b) { return a > b ? (a = b, true) : false; } struct IOSetup { IOSetup() { std::cin.tie(nullptr); std::ios_base::sync_with_stdio(false); std::cout << fixed << setprecision(20); } } iosetup; template struct FenwickTree { explicit FenwickTree(const int n, const Abelian ID = 0) : n(n), ID(ID), data(n, ID) {} void add(int idx, const Abelian val) { for (; idx < n; idx |= idx + 1) { data[idx] += val; } } Abelian sum(int idx) const { Abelian res = ID; for (--idx; idx >= 0; idx = (idx & (idx + 1)) - 1) { res += data[idx]; } return res; } Abelian sum(const int left, const int right) const { return left < right ? sum(right) - sum(left) : ID; } Abelian operator[](const int idx) const { return sum(idx, idx + 1); } int lower_bound(Abelian val) const { if (val <= ID) return 0; int res = 0, exponent = 1; while (exponent <= n) exponent <<= 1; for (int mask = exponent >> 1; mask > 0; mask >>= 1) { const int idx = res + mask - 1; if (idx < n && data[idx] < val) { val -= data[idx]; res += mask; } } return res; } private: const int n; const Abelian ID; std::vector data; }; template struct FenwickTreeSupportingRangeAddQuery { explicit FenwickTreeSupportingRangeAddQuery( const int n_, const Abelian ID = 0) : n(n_ + 1), ID(ID) { data_const.assign(n, ID); data_linear.assign(n, ID); } void add(int left, const int right, const Abelian val) { if (right < ++left) return; for (int i = left; i < n; i += i & -i) { data_const[i] -= val * (left - 1); data_linear[i] += val; } for (int i = right + 1; i < n; i += i & -i) { data_const[i] += val * right; data_linear[i] -= val; } } Abelian sum(const int idx) const { Abelian res = ID; for (int i = idx; i > 0; i -= i & -i) { res += data_linear[i]; } res *= idx; for (int i = idx; i > 0; i -= i & -i) { res += data_const[i]; } return res; } Abelian sum(const int left, const int right) const { return left < right ? sum(right) - sum(left) : ID; } Abelian operator[](const int idx) const { return sum(idx, idx + 1); } private: const int n; const Abelian ID; std::vector data_const, data_linear; }; int main() { int n; cin >> n; vector p(n); REP(i, n) cin >> p[i], --p[i]; vector inv(n); REP(i, n) inv[p[i]] = i; FenwickTree bit(n); FenwickTreeSupportingRangeAddQuery idx(n); REP(i, n) idx.add(i + 1, n, 1); vector x, y; auto op = [&](int i) -> void { x.emplace_back(i); y.emplace_back(idx[inv[i]]); idx.add(inv[i], n, -1); }; for (int i = n - 1; i >= 0;) { int j = i; for (int l = -1, r = n; j >= 0; --j) { if (l < inv[j] && inv[j] < r && idx[inv[j]] % 2 == 1) { op(j); for (; i > j; --i) { bit.add(inv[j], -1); op(i); } break; } else if ((idx[inv[j]] - bit.sum(inv[j])) % 2 == 0) { chmax(l, inv[j]); } else { chmin(r, inv[j]); } bit.add(inv[j], 1); } if (j == -1) { cout << "No\n"; return 0; } i = j - 1; } reverse(ALL(x)); reverse(ALL(y)); cout << "Yes\n"; REP(i, n) cout << x[i] + 1 << ' ' << y[i] + 1 << '\n'; return 0; }