#include #include void add_BIT(int N, int BIT[], int i, int k) { while (i <= N) { BIT[i] += k; i += (i & -i); } } int sum_BIT(int BIT[], int r) { int sum = 0; while (r > 0) { sum += BIT[r]; r -= (r & -r); } return sum; } void add_xor_BIT(int N, int BIT[], int i) { while (i <= N) { BIT[i] ^= 1; i += (i & -i); } } int sum_xor_BIT(int BIT[], int r) { int sum = 0; while (r > 0) { sum ^= BIT[r]; r -= (r & -r); } return sum; } struct timeval t; double beg, cur; int memo[200001], r; int recursion(int N, int l, int P_inv[], int BIT[], int ans[]) { if (l > N) return 1; else if (memo[l] != 0) return 0; gettimeofday(&t, NULL); cur = t.tv_sec + (double)t.tv_usec / 1000000; if (cur - beg > 1.95) return 0; int i; if (sum_xor_BIT(BIT, P_inv[l] - 1) == 0) { add_xor_BIT(N, BIT, P_inv[l]); ans[0] = l; if (recursion(N, l + 1, P_inv, BIT, &(ans[1])) != 0) return 1; add_xor_BIT(N, BIT, P_inv[l]); } if (P_inv[l] % 2 == 0) { for (i = l + 1; i < r; i++) { gettimeofday(&t, NULL); cur = t.tv_sec + (double)t.tv_usec / 1000000; if (cur - beg > 1.95) return 0; if (sum_xor_BIT(BIT, P_inv[i] - 1) != 0) break; add_xor_BIT(N, BIT, P_inv[i]); ans[i-l-1] = i; if (sum_xor_BIT(BIT, P_inv[l] - 1) == 0) { add_xor_BIT(N, BIT, P_inv[l]); ans[i-l] = l; if (recursion(N, i + 1, P_inv, BIT, &(ans[i-l+1])) != 0) return 1; add_xor_BIT(N, BIT, P_inv[l]); } } } else { for (i = l + 1; i <= N; i++) { gettimeofday(&t, NULL); cur = t.tv_sec + (double)t.tv_usec / 1000000; if (cur - beg > 1.95) return 0; if (sum_xor_BIT(BIT, P_inv[i] - 1) != 0) break; add_xor_BIT(N, BIT, P_inv[i]); ans[i-l-1] = i; if (sum_xor_BIT(BIT, P_inv[l] - 1) == 0) { add_xor_BIT(N, BIT, P_inv[l]); ans[i-l] = l; if (recursion(N, i + 1, P_inv, BIT, &(ans[i-l+1])) != 0) return 1; add_xor_BIT(N, BIT, P_inv[l]); } } } for (i--; i > l; i--) add_xor_BIT(N, BIT, P_inv[i]); memo[l] = -1; while (memo[r] != 0) r--; return 0; } int solve(int N, int P[], int ans[]) { static int i, P_inv[200001], BIT[200001]; for (i = 1, memo[0] = 0; i <= N; i++) { P_inv[P[i]] = i; BIT[i] = 0; memo[i] = 0; } r = N; return recursion(N, 1, P_inv, BIT, &(ans[1])); } int main() { gettimeofday(&t, NULL); beg = t.tv_sec + (double)t.tv_usec / 1000000; int i, N, P[200001], P_inv[200001], ans[200001], BIT[200001] = {}; scanf("%d", &N); for (i = 1; i <= N; i++) scanf("%d", &(P[i])); if (solve(N, P, ans) == 0) printf("No\n"); else { printf("Yes\n"); for (i = 1; i <= N; i++) P_inv[P[i]] = i; for (i = 1; i <= N; i++) { printf("%d %d\n", ans[i], sum_BIT(BIT, P_inv[ans[i]] - 1) + 1); add_BIT(N, BIT, P_inv[ans[i]], 1); } } fflush(stdout); return 0; }