P1712 [NOI2016] 区间

https://www.luogu.com.cn/record/87172981

LibreOJ/2086/2086.cpp

@@ -0,0 +1,113 @@
+#include <iostream>
+#include <algorithm>
+#include <limits>
+#include <utility>
+#include <vector>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 5e5 + 5;
+
+struct node {
+    int l, r, m, d;
+
+    node(int _l = 0, int _r = 0)
+        : l(_l), r(_r), m(0), d(0) {}
+} tr[N << 3];
+
+void pushup(int u) {
+    tr[u].m = std::max(tr[u << 1].m, tr[u << 1 | 1].m);
+}
+
+void pushdown(int u) {
+    if (!tr[u].d) return;
+
+    tr[u << 1].d += tr[u].d;
+    tr[u << 1 | 1].d += tr[u].d;
+
+    tr[u << 1].m += tr[u].d;
+    tr[u << 1 | 1].m += tr[u].d;
+
+    tr[u].d = 0;
+}
+
+void build(int u, int l, int r) {
+    tr[u] = node(l, r);
+
+    if (l == r) return;
+
+    int mid = l + r >> 1;
+    build(u << 1, l, mid);
+    build(u << 1 | 1, mid + 1, r);
+}
+
+void modify(int u, int l, int r, int v) {
+    if (l <= tr[u].l && tr[u].r <= r) {
+        tr[u].d += v;
+        tr[u].m += v;
+
+        return;
+    }
+
+    pushdown(u);
+
+    int mid = tr[u].l + tr[u].r >> 1;
+    if (l <= mid) modify(u << 1, l, r, v);
+    if (r > mid) modify(u << 1 | 1, l, r, v);
+
+    pushup(u);
+}
+
+int n, m, ans = std::numeric_limits<int>::max();
+std::pair<int, int> seg[N];
+std::vector<int> nums;
+
+int len(int p) {
+    return nums[seg[p].second - 1] - nums[seg[p].first - 1];
+}
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    int n, m;
+
+    cin >> n >> m;
+
+    for (int i = 1; i <= n; i++) {
+        cin >> seg[i].first >> seg[i].second;
+
+        nums.emplace_back(seg[i].first);
+        nums.emplace_back(seg[i].second);
+    }
+
+    std::sort(seg + 1, seg + 1 + n, [&](const std::pair<int, int> &a, const std::pair<int, int> &b) {
+        return a.second - a.first < b.second - b.first;
+    });
+
+    std::sort(nums.begin(), nums.end());
+    nums.erase(std::unique(nums.begin(), nums.end()), nums.end());
+
+    for (int i = 1; i <= n; i++) {
+        seg[i].first = std::lower_bound(nums.begin(), nums.end(), seg[i].first) - nums.begin() + 1;
+        seg[i].second = std::lower_bound(nums.begin(), nums.end(), seg[i].second) - nums.begin() + 1;
+    }
+
+    build(1, 1, nums.size());
+
+    for (int i = 1, l = 1; i <= n; i++) {
+        modify(1, seg[i].first, seg[i].second, 1);
+
+        while (tr[1].m >= m) {
+            ans = std::min(ans, len(i) - len(l));
+            modify(1, seg[l].first, seg[l].second, -1);
+            l++;
+        }
+    }
+
+    cout << (ans == std::numeric_limits<int>::max() ? -1 : ans) << endl;
+
+    return 0;
+}

Luogu/P1712/P1712.cpp

@@ -0,0 +1,113 @@
+#include <iostream>
+#include <algorithm>
+#include <limits>
+#include <utility>
+#include <vector>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 5e5 + 5;
+
+struct node {
+    int l, r, m, d;
+
+    node(int _l = 0, int _r = 0)
+        : l(_l), r(_r), m(0), d(0) {}
+} tr[N << 3];
+
+void pushup(int u) {
+    tr[u].m = std::max(tr[u << 1].m, tr[u << 1 | 1].m);
+}
+
+void pushdown(int u) {
+    if (!tr[u].d) return;
+
+    tr[u << 1].d += tr[u].d;
+    tr[u << 1 | 1].d += tr[u].d;
+
+    tr[u << 1].m += tr[u].d;
+    tr[u << 1 | 1].m += tr[u].d;
+
+    tr[u].d = 0;
+}
+
+void build(int u, int l, int r) {
+    tr[u] = node(l, r);
+
+    if (l == r) return;
+
+    int mid = l + r >> 1;
+    build(u << 1, l, mid);
+    build(u << 1 | 1, mid + 1, r);
+}
+
+void modify(int u, int l, int r, int v) {
+    if (l <= tr[u].l && tr[u].r <= r) {
+        tr[u].d += v;
+        tr[u].m += v;
+
+        return;
+    }
+
+    pushdown(u);
+
+    int mid = tr[u].l + tr[u].r >> 1;
+    if (l <= mid) modify(u << 1, l, r, v);
+    if (r > mid) modify(u << 1 | 1, l, r, v);
+
+    pushup(u);
+}
+
+int n, m, ans = std::numeric_limits<int>::max();
+std::pair<int, int> seg[N];
+std::vector<int> nums;
+
+int len(int p) {
+    return nums[seg[p].second - 1] - nums[seg[p].first - 1];
+}
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    int n, m;
+
+    cin >> n >> m;
+
+    for (int i = 1; i <= n; i++) {
+        cin >> seg[i].first >> seg[i].second;
+
+        nums.emplace_back(seg[i].first);
+        nums.emplace_back(seg[i].second);
+    }
+
+    std::sort(seg + 1, seg + 1 + n, [&](const std::pair<int, int> &a, const std::pair<int, int> &b) {
+        return a.second - a.first < b.second - b.first;
+    });
+
+    std::sort(nums.begin(), nums.end());
+    nums.erase(std::unique(nums.begin(), nums.end()), nums.end());
+
+    for (int i = 1; i <= n; i++) {
+        seg[i].first = std::lower_bound(nums.begin(), nums.end(), seg[i].first) - nums.begin() + 1;
+        seg[i].second = std::lower_bound(nums.begin(), nums.end(), seg[i].second) - nums.begin() + 1;
+    }
+
+    build(1, 1, nums.size());
+
+    for (int i = 1, l = 1; i <= n; i++) {
+        modify(1, seg[i].first, seg[i].second, 1);
+
+        while (tr[1].m >= m) {
+            ans = std::min(ans, len(i) - len(l));
+            modify(1, seg[l].first, seg[l].second, -1);
+            l++;
+        }
+    }
+
+    cout << (ans == std::numeric_limits<int>::max() ? -1 : ans) << endl;
+
+    return 0;
+}

S2OJ/1585/1585.cpp

@@ -0,0 +1,47 @@
+#include <iostream>
+#include <algorithm>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 305;
+const int mod = 998244353;
+
+int n, k, a[N], f[N][N][N], g[N][N][N];
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n >> k;
+
+    for (int i = 1; i <= n; i++) {
+        cin >> a[i];
+    }
+
+    std::sort(a + 1, a + 1 + n);
+
+    for (int i = 0; i <= k; i++) {
+        g[0][0][i] = 1;
+    }
+
+    for (int i = 1; i <= n; i++) {
+        for (int j = 0; j <= k; j++) {
+            for (int l = 0; l <= k; l++) {
+                int p = std::min(a[i] - a[i - 1] + l, k);
+                if (p < 0) continue;
+
+                if (l <= j) {
+                    f[i][j][l] = (f[i][j][l] + g[i - 1][j - l][p]) % mod;
+                }
+
+                g[i][j][l] = (f[i][j][l] + (l ? g[i][j][l - 1] : 0)) % mod;
+            }
+        }
+    }
+
+    cout << g[n][k][k] << endl;
+
+    return 0;
+}

S2OJ/1586/1586.cpp

@@ -0,0 +1,128 @@
+#include <iostream>
+#include <algorithm>
+#include <array>
+#include <numeric>
+#include <tuple>
+#include <vector>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int INF = 0x3f3f3f3f;
+
+class DSU {
+  private:
+    std::vector<int> fa;
+
+  public:
+    DSU(int _n = 0)
+        : fa(_n) {
+        std::iota(fa.begin(), fa.end(), 0);
+    }
+
+    int find(int x) {
+        return fa[x] == x ? x : fa[x] = find(fa[x]);
+    }
+
+    bool merge(int x, int y) {
+        x = find(x);
+        y = find(y);
+
+        fa[x] = y;
+
+        return x != y;
+    }
+};
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    int t;
+
+    cin >> t;
+
+    while (t--) {
+        int n, m;
+
+        cin >> n >> m;
+
+        std::vector<int> a(n), b(n);
+        std::vector<std::tuple<int, int, int>> edges;
+        std::vector<bool> f(1 << n, false);
+
+        for (int i = 0, u, v, w; i < m; i++) {
+            cin >> u >> v >> w;
+
+            edges.emplace_back(u - 1, v - 1, w);
+        }
+
+        for (int i = 0; i < n; i++) {
+            cin >> a[i] >> b[i];
+        }
+
+        auto check = [&](int s) -> bool {
+            auto in_block = [&](int x) -> bool {
+                return s >> x & 1;
+            };
+
+            int sum = 0, root = 0;
+            DSU dsu(n);
+            std::vector<std::tuple<int, int, int>> block_edges;
+
+            for (auto& edge : edges) {
+                int u, v;
+
+                std::tie(u, v, std::ignore) = edge;
+
+                if (in_block(u) && in_block(v)) {
+                    block_edges.emplace_back(edge);
+                }
+            }
+
+            std::sort(block_edges.begin(), block_edges.end(), [](auto& lhs, auto& rhs) {
+                return std::get<2>(lhs) < std::get<2>(rhs);
+            });
+
+            for (int i = 0; i < n; i++) {
+                if (in_block(i)) sum += a[i] - b[i];
+            }
+
+            for (auto& edge : block_edges) {
+                int u, v, w;
+
+                std::tie(u, v, w) = edge;
+
+                if (dsu.merge(u, v)) sum -= w;
+            }
+
+            for (int i = 0; i < n; i++) {
+                if (in_block(i) && dsu.find(i) == i) {
+                    root = i;
+                }
+            }
+
+            for (int i = 0; i < n; i++) {
+                if (in_block(i) && dsu.find(i) != root) {
+                    return false;
+                }
+            }
+
+            return sum >= 0;
+        };
+
+        f[0] = true;
+        for (int s = 1; s < 1 << n; s++) {
+            f[s] = check(s);
+
+            for (int i = s; i; i = (i - 1) & s) {
+                f[s] = f[s] || f[i] && f[s ^ i];
+            }
+        }
+
+        cout << (f[(1 << n) - 1] ? "Yes" : "No") << endl;
+    }
+
+    return 0;
+}