sotanishy's code snippets for competitive programming
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#define PROBLEM "https://judge.yosupo.jp/problem/area_of_union_of_rectangles" #include <bits/stdc++.h> #include "../../misc/rectangle_union.hpp" using namespace std; using ll = long long; int main() { ios_base::sync_with_stdio(false); cin.tie(nullptr); int N; cin >> N; vector<tuple<ll, ll, ll, ll>> rects(N); for (int i = 0; i < N; ++i) { int l, d, r, u; cin >> l >> d >> r >> u; rects[i] = {l, d, r, u}; } cout << area_of_union_of_rectangles(rects) << endl; }
#line 1 "test/yosupo/area_of_union_of_rectangles.test.cpp" #define PROBLEM "https://judge.yosupo.jp/problem/area_of_union_of_rectangles" #include <bits/stdc++.h> #line 4 "misc/rectangle_union.hpp" #line 3 "data-structure/segtree/lazy_segment_tree.hpp" #include <bit> #line 6 "data-structure/segtree/lazy_segment_tree.hpp" template <typename M, typename O, typename M::T (*act)(typename M::T, typename O::T)> class LazySegmentTree { using T = M::T; using E = O::T; public: LazySegmentTree() = default; explicit LazySegmentTree(int n) : LazySegmentTree(std::vector<T>(n, M::id())) {} explicit LazySegmentTree(const std::vector<T>& v) : size(std::bit_ceil(v.size())), node(2 * size, M::id()), lazy(2 * size, O::id()) { std::ranges::copy(v, node.begin() + size); for (int i = size - 1; i > 0; --i) { node[i] = M::op(node[2 * i], node[2 * i + 1]); } } T operator[](int k) { return fold(k, k + 1); } void update(int l, int r, const E& x) { update(l, r, x, 1, 0, size); } T fold(int l, int r) { return fold(l, r, 1, 0, size); } T fold_all() { push(1); return node[1]; } template <typename F> int find_first(int l, F cond) { T v = M::id(); return find_first(l, size, 1, 0, size, v, cond); } template <typename F> int find_last(int r, F cond) { T v = M::id(); return find_last(0, r, 1, 0, size, v, cond); } private: int size; std::vector<T> node; std::vector<E> lazy; void push(int k) { if (lazy[k] == O::id()) return; if (k < size) { lazy[2 * k] = O::op(lazy[2 * k], lazy[k]); lazy[2 * k + 1] = O::op(lazy[2 * k + 1], lazy[k]); } node[k] = act(node[k], lazy[k]); lazy[k] = O::id(); } void update(int a, int b, const E& x, int k, int l, int r) { push(k); if (r <= a || b <= l) return; if (a <= l && r <= b) { lazy[k] = O::op(lazy[k], x); push(k); return; } int m = std::midpoint(l, r); update(a, b, x, 2 * k, l, m); update(a, b, x, 2 * k + 1, m, r); node[k] = M::op(node[2 * k], node[2 * k + 1]); } T fold(int a, int b, int k, int l, int r) { push(k); if (r <= a || b <= l) return M::id(); if (a <= l && r <= b) return node[k]; int m = std::midpoint(l, r); return M::op(fold(a, b, 2 * k, l, m), fold(a, b, 2 * k + 1, m, r)); } template <typename F> int find_first(int a, int b, int k, int l, int r, T& v, F cond) { push(k); if (r <= a) return -1; if (b <= l) return l; if (a <= l && r <= b && !cond(M::op(v, node[k]))) { v = M::op(v, node[k]); return -1; } if (r - l == 1) return r; int m = std::midpoint(l, r); int res = find_first(a, b, 2 * k, l, m, v, cond); if (res != -1) return res; return find_first(a, b, 2 * k + 1, m, r, v, cond); } template <typename F> int find_last(int a, int b, int k, int l, int r, T& v, F cond) { push(k); if (b <= l) return -1; if (r <= a) return r; if (a <= l && r <= b && !cond(M::op(node[k], v))) { v = M::op(node[k], v); return -1; } if (r - l == 1) return l; int m = std::midpoint(l, r); int res = find_last(a, b, 2 * k + 1, m, r, v, cond); if (res != -1) return res; return find_last(a, b, 2 * k, l, m, v, cond); } }; #line 6 "misc/rectangle_union.hpp" /** * @brief Area of Union of Rectangles */ struct CountMinMonoid { using T = std::pair<int, int>; // min, count static T id() { return {(1u << 31) - 1, 0}; } static T op(T a, T b) { if (a.first < b.first) return a; if (a.first > b.first) return b; return {a.first, a.second + b.second}; } }; struct AddMonoid { using T = int; static T id() { return 0; } static T op(T a, T b) { return a + b; } }; CountMinMonoid::T act(CountMinMonoid::T a, AddMonoid::T b) { return {a.first + b, a.second}; } // rectangles are given in the form (l, d, r, u) long long area_of_union_of_rectangles( const std::vector<std::tuple<long long, long long, long long, long long>>& rects) { std::vector<long long> xs, ys; for (auto [l, d, r, u] : rects) { xs.push_back(l); xs.push_back(r); ys.push_back(d); ys.push_back(u); } std::ranges::sort(xs); xs.erase(std::ranges::unique(xs).begin(), xs.end()); std::ranges::sort(ys); ys.erase(std::ranges::unique(ys).begin(), ys.end()); std::vector<std::vector<std::tuple<long long, long long, int>>> update( ys.size()); for (auto [l, d, r, u] : rects) { int cl = std::ranges::lower_bound(xs, l) - xs.begin(); int cd = std::ranges::lower_bound(ys, d) - ys.begin(); int cr = std::ranges::lower_bound(xs, r) - xs.begin(); int cu = std::ranges::lower_bound(ys, u) - ys.begin(); update[cd].push_back({cl, cr, 1}); update[cu].push_back({cl, cr, -1}); } std::vector<std::pair<int, int>> init(xs.size() - 1); for (int x = 0; x < (int)xs.size() - 1; ++x) { init[x] = {0, xs[x + 1] - xs[x]}; } LazySegmentTree<CountMinMonoid, AddMonoid, act> st(init); long long ans = 0; long long xlen = xs.back() - xs[0]; for (int y = 0; y < (int)ys.size() - 1; ++y) { for (auto [l, r, diff] : update[y]) { st.update(l, r, diff); } auto [minval, len0] = st.fold_all(); if (minval > 0) len0 = 0; ans += (xlen - len0) * (ys[y + 1] - ys[y]); } return ans; } #line 6 "test/yosupo/area_of_union_of_rectangles.test.cpp" using namespace std; using ll = long long; int main() { ios_base::sync_with_stdio(false); cin.tie(nullptr); int N; cin >> N; vector<tuple<ll, ll, ll, ll>> rects(N); for (int i = 0; i < N; ++i) { int l, d, r, u; cin >> l >> d >> r >> u; rects[i] = {l, d, r, u}; } cout << area_of_union_of_rectangles(rects) << endl; }