#include <bits/stdc++.h> using namespace std; typedef long long int LL; const LL M = 1000000007LL; struct BST { int root; BST* parent; BST* left; BST* right; BST(int _root, BST* _parent) { root = _root; parent = _parent; left = right = nullptr; } BST(int _root, BST* _parent, BST* _left, BST* _right) { root = _root; parent = _parent; left = _left; right = _right; } void construct(const vector<vector<int>>& child) { for (int x : child[root]) { BST* child_node = new BST(x, this); if (x < root) left = child_node; if (x > root) right = child_node; child_node->construct(child); } } BST(const vector<int>& seq) { vector<vector<int>> child(seq.size() + 1); for (int i = 0; i < seq.size(); i++) child[max(0, seq[i])].push_back(i + 1); *this = BST(child[0][0], nullptr); construct(child); } void debug_print(bool from_root = false) { if (from_root) { BST* node = this; while (node->parent != nullptr) node = node->parent; node->debug_print(); cerr << "\n"; return; } cerr << "BST(root = " << root; cerr << ", parent = "; if (parent != nullptr) cerr << parent->root; else cerr << "nullptr"; cerr << ", left = "; if (left != nullptr) cerr << left->root; else cerr << "nullptr"; cerr << ", right = "; if (right != nullptr) cerr << right->root; else cerr << "nullptr"; cerr << ")\n"; if (left != nullptr) left->debug_print(); if (right != nullptr) right->debug_print(); } void left_rotate() { BST* v = this; BST* w = right; //cerr << "running left rotate on " << v->root << "\n"; assert(w->left == nullptr); if (parent != nullptr) { if ((parent->right != nullptr) && (parent->right->root == v->root)) v->parent->right = w; else v->parent->left = w; } w->parent = v->parent; v->parent = w; w->left = v; v->right = nullptr; //debug_print(true); } void right_rotate() { BST* v = this; BST* w = left; //cerr << "running right rotate on " << v->root << "\n"; assert(w->right == nullptr); if (parent != nullptr) { if ((parent->right != nullptr) && (parent->right->root == v->root)) v->parent->right = w; else v->parent->left = w; } w->parent = v->parent; v->parent = w; w->right = v; v->left = nullptr; //debug_print(true); } BST* find(int k) { if (k < root) return (left != nullptr) ? left->find(k) : nullptr; if (k > root) return (right != nullptr) ? right->find(k) : nullptr; return this; } LL pathify(int min_root, int max_root) { LL result = 0; if ((left != nullptr) && (root > min_root)) result += left->pathify(min(root, min_root), max(root, max_root)); if ((right != nullptr) && (root < max_root)) result += right->pathify(min(root, min_root), max(root, max_root)); bool shift_left = (parent == nullptr) || (root < parent->root); BST* go_node = this; if (shift_left) { while (go_node->right != nullptr) { go_node->left_rotate(); result++; go_node = go_node->parent; } } else { while (go_node->left != nullptr) { go_node->right_rotate(); result++; go_node = go_node->parent; } } return result; } LL transform(BST* other) { //cerr << "transforming my_root " << root << " into other_root " << other->root << "\n"; LL result = 0; BST* go_node = this; if (other->root < root) { //cerr << "running pathify (" << other->root << ", " << root << ")\n"; result += left->pathify(other->root, root); while (go_node->root != other->root) { go_node->right_rotate(); result++; go_node = go_node->parent; } } else if (other->root > root) { //cerr << "running pathify (" << root << ", " << other->root << ")\n"; result += right->pathify(root, other->root); while (go_node->root != other->root) { go_node->left_rotate(); result++; go_node = go_node->parent; } } //cerr << "now root " << other->root << " is satisfied!\n"; if (other->left != nullptr) { //cerr << "we need to satisfy " << other->left->root << "\n"; if (go_node->left != nullptr) result += go_node->left->transform(other->left); else { assert(false); } } if (other->right != nullptr) { //cerr << "we need to satisfy " << other->right->root << "\n"; if (go_node->right != nullptr) result += go_node->right->transform(other->right); else { assert(false); } } return result; } }; int main() { ios_base::sync_with_stdio(false); int n; cin >> n; vector<int> seq1(n); for (int i = 0; i < n; i++) cin >> seq1[i]; vector<int> seq2(n); for (int i = 0; i < n; i++) cin >> seq2[i]; BST tree1(seq1); BST tree2(seq2); /* cerr << "tree1:\n"; tree1.debug_print(); cerr << "tree2:\n"; tree2.debug_print(); cerr << "\n\n"; */ cout << tree1.transform(&tree2) % M << "\n"; /* cerr << "final state of tree1:\n"; BST* t1 = &tree1; while (t1->parent != nullptr) t1 = t1->parent; t1->debug_print(); */ return 0; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 | #include <bits/stdc++.h> using namespace std; typedef long long int LL; const LL M = 1000000007LL; struct BST { int root; BST* parent; BST* left; BST* right; BST(int _root, BST* _parent) { root = _root; parent = _parent; left = right = nullptr; } BST(int _root, BST* _parent, BST* _left, BST* _right) { root = _root; parent = _parent; left = _left; right = _right; } void construct(const vector<vector<int>>& child) { for (int x : child[root]) { BST* child_node = new BST(x, this); if (x < root) left = child_node; if (x > root) right = child_node; child_node->construct(child); } } BST(const vector<int>& seq) { vector<vector<int>> child(seq.size() + 1); for (int i = 0; i < seq.size(); i++) child[max(0, seq[i])].push_back(i + 1); *this = BST(child[0][0], nullptr); construct(child); } void debug_print(bool from_root = false) { if (from_root) { BST* node = this; while (node->parent != nullptr) node = node->parent; node->debug_print(); cerr << "\n"; return; } cerr << "BST(root = " << root; cerr << ", parent = "; if (parent != nullptr) cerr << parent->root; else cerr << "nullptr"; cerr << ", left = "; if (left != nullptr) cerr << left->root; else cerr << "nullptr"; cerr << ", right = "; if (right != nullptr) cerr << right->root; else cerr << "nullptr"; cerr << ")\n"; if (left != nullptr) left->debug_print(); if (right != nullptr) right->debug_print(); } void left_rotate() { BST* v = this; BST* w = right; //cerr << "running left rotate on " << v->root << "\n"; assert(w->left == nullptr); if (parent != nullptr) { if ((parent->right != nullptr) && (parent->right->root == v->root)) v->parent->right = w; else v->parent->left = w; } w->parent = v->parent; v->parent = w; w->left = v; v->right = nullptr; //debug_print(true); } void right_rotate() { BST* v = this; BST* w = left; //cerr << "running right rotate on " << v->root << "\n"; assert(w->right == nullptr); if (parent != nullptr) { if ((parent->right != nullptr) && (parent->right->root == v->root)) v->parent->right = w; else v->parent->left = w; } w->parent = v->parent; v->parent = w; w->right = v; v->left = nullptr; //debug_print(true); } BST* find(int k) { if (k < root) return (left != nullptr) ? left->find(k) : nullptr; if (k > root) return (right != nullptr) ? right->find(k) : nullptr; return this; } LL pathify(int min_root, int max_root) { LL result = 0; if ((left != nullptr) && (root > min_root)) result += left->pathify(min(root, min_root), max(root, max_root)); if ((right != nullptr) && (root < max_root)) result += right->pathify(min(root, min_root), max(root, max_root)); bool shift_left = (parent == nullptr) || (root < parent->root); BST* go_node = this; if (shift_left) { while (go_node->right != nullptr) { go_node->left_rotate(); result++; go_node = go_node->parent; } } else { while (go_node->left != nullptr) { go_node->right_rotate(); result++; go_node = go_node->parent; } } return result; } LL transform(BST* other) { //cerr << "transforming my_root " << root << " into other_root " << other->root << "\n"; LL result = 0; BST* go_node = this; if (other->root < root) { //cerr << "running pathify (" << other->root << ", " << root << ")\n"; result += left->pathify(other->root, root); while (go_node->root != other->root) { go_node->right_rotate(); result++; go_node = go_node->parent; } } else if (other->root > root) { //cerr << "running pathify (" << root << ", " << other->root << ")\n"; result += right->pathify(root, other->root); while (go_node->root != other->root) { go_node->left_rotate(); result++; go_node = go_node->parent; } } //cerr << "now root " << other->root << " is satisfied!\n"; if (other->left != nullptr) { //cerr << "we need to satisfy " << other->left->root << "\n"; if (go_node->left != nullptr) result += go_node->left->transform(other->left); else { assert(false); } } if (other->right != nullptr) { //cerr << "we need to satisfy " << other->right->root << "\n"; if (go_node->right != nullptr) result += go_node->right->transform(other->right); else { assert(false); } } return result; } }; int main() { ios_base::sync_with_stdio(false); int n; cin >> n; vector<int> seq1(n); for (int i = 0; i < n; i++) cin >> seq1[i]; vector<int> seq2(n); for (int i = 0; i < n; i++) cin >> seq2[i]; BST tree1(seq1); BST tree2(seq2); /* cerr << "tree1:\n"; tree1.debug_print(); cerr << "tree2:\n"; tree2.debug_print(); cerr << "\n\n"; */ cout << tree1.transform(&tree2) % M << "\n"; /* cerr << "final state of tree1:\n"; BST* t1 = &tree1; while (t1->parent != nullptr) t1 = t1->parent; t1->debug_print(); */ return 0; } |