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OI-codes/Luogu/P3377/P3377.cpp

142 lines
3.0 KiB
C++

#include <iostream>
#include <functional>
#include <memory>
#include <stack>
#include <vector>
using std::cin;
using std::cout;
const char endl = '\n';
template <typename T, class Compare = std::less<T>>
class LeftistTree : public std::enable_shared_from_this<LeftistTree<T, Compare>> {
public:
using pointer_type = std::shared_ptr<LeftistTree<T, Compare>>;
protected:
static Compare comp;
private:
size_t dist;
pointer_type lchild, rchild;
std::weak_ptr<LeftistTree<T, Compare>> root;
public:
T id, val;
LeftistTree(const T& _val = 0, const T& _id = 0)
: dist(0),
lchild(nullptr),
rchild(nullptr),
root(),
id(_id),
val(_val) {}
pointer_type find_root() {
std::stack<pointer_type> st;
pointer_type cur = this->shared_from_this();
st.emplace(cur);
while (auto ptr = cur->root.lock()) {
st.emplace(cur = ptr);
}
while (!st.empty()) {
auto ptr = st.top();
st.pop();
ptr->root = cur;
}
cur->root.reset();
return cur;
}
void erase() {
if (lchild) lchild->root.reset();
if (rchild) rchild->root.reset();
root = merge(lchild, rchild);
}
static pointer_type merge(pointer_type x, pointer_type y) {
if (!x) return y;
if (!y) return x;
if (comp(x->val, y->val) || x->val == y->val && comp(x->id, y->id)) std::swap(x, y);
x->rchild = merge(x->rchild, y);
if (!x->lchild || x->lchild->dist < x->rchild->dist) std::swap(x->lchild, x->rchild);
if (x->lchild) x->lchild->root = x;
if (x->rchild) x->rchild->root = x;
x->dist = x->rchild ? x->rchild->dist + 1 : 0;
return x;
}
};
int main() {
std::ios::sync_with_stdio(false);
cin.tie(nullptr);
int n, m;
cin >> n >> m;
std::vector<bool> exists(n + 1, true);
std::vector<LeftistTree<int, std::greater<>>::pointer_type> tr(n + 1);
for (int i = 1, x; i <= n; i++) {
cin >> x;
tr[i] = std::make_shared<decltype(tr)::value_type::element_type>(x, i);
}
while (m--) {
int op;
cin >> op;
if (op == 1) {
int x, y;
cin >> x >> y;
if (exists[x] && exists[y]) {
auto fx = tr[x]->find_root(),
fy = tr[y]->find_root();
if (fx != fy) {
decltype(tr)::value_type::element_type::merge(fx, fy);
}
}
} else { // op == 2
int x;
cin >> x;
if (exists[x]) {
auto fx = tr[x]->find_root();
if (exists[fx->id]) {
cout << fx->val << endl;
fx->erase();
exists[fx->id] = false;
} else {
cout << -1 << endl;
}
} else {
cout << -1 << endl;
}
}
}
return 0;
}