LibreOJ/2071/2071.cpp

@@ -1,78 +0,0 @@
-#include <iostream>
-#include <algorithm>
-#include <array>
-#include <iomanip>
-#include <limits>
-#include <vector>
-
-using std::cin;
-using std::cout;
-const char endl = '\n';
-
-const int N = 2505;
-const double eps = 1e-4;
-
-int k, n;
-std::array<int, N> siz;
-std::array<double, N> d;
-std::array<std::array<double, N>, N> f;
-std::array<std::vector<int>, N> g;
-std::array<std::pair<int, int>, N> a;
-
-void dfs(int u) {
-    f[u][1] = d[u];
-    siz[u] = 1;
-
-    for (int v : g[u]) {
-        dfs(v);
-
-        siz[u] += siz[v];
-
-        for (int i = std::min(siz[u], k + 1); i; i--) {
-            for (int j = 0; j <= std::min(siz[v], i - 1); j++) {
-                f[u][i] = std::max(f[u][i], f[u][i - j] + f[v][j]);
-            }
-        }
-    }
-}
-
-bool check(double mid) {
-    for (int i = 1; i <= n; i++) {
-        d[i] = static_cast<double>(a[i].second) - mid * a[i].first;
-    }
-
-    std::for_each(f.begin(), f.end(), [&](auto &x) {
-        std::fill(x.begin(), x.end(), std::numeric_limits<int>::min());
-    });
-
-    dfs(0);
-
-    return f[0][k + 1] >= 0;
-}
-
-int main() {
-    std::ios::sync_with_stdio(false);
-    cin.tie(nullptr);
-
-    cin >> k >> n;
-
-    for (int i = 1, r; i <= n; i++) {
-        cin >> a[i].first >> a[i].second >> r;
-
-        g[r].emplace_back(i);
-    }
-
-    double l = 0,
-           r = 10000;
-
-    while (r - l > eps) {
-        double mid = (l + r) / 2;
-
-        if (check(mid)) l = mid;
-        else r = mid;
-    }
-
-    cout << std::fixed << std::setprecision(3) << l << endl;
-
-    return 0;
-}

LibreOJ/2431/2431.cpp

@@ -1,64 +0,0 @@
-#include <iostream>
-#include <algorithm>
-#include <array>
-#include <vector>
-
-using std::cin;
-using std::cout;
-const char endl = '\n';
-
-const int N = 5005;
-
-int n, max_dep;
-long long ans;
-std::vector<int> g[N];
-std::array<int, N> f1, f2, cnt;
-
-void dfs(int u, int f, int d) {
-    cnt[d]++;
-    max_dep = std::max(max_dep, d);
-
-    for (int v : g[u]) {
-        if (v == f) continue;
-
-        dfs(v, u, d + 1);
-    }
-}
-
-int main() {
-    std::ios::sync_with_stdio(false);
-    cin.tie(nullptr);
-
-    cin >> n;
-
-    for (int i = 1, u, v; i < n; i++) {
-        cin >> u >> v;
-
-        g[u].emplace_back(v);
-        g[v].emplace_back(u);
-    }
-
-    dfs(1, 0, 1);
-
-    for (int i = 1; i <= n; i++) {
-        std::fill(f1.begin(), f1.end(), 0);
-        std::fill(f2.begin(), f2.end(), 0);
-
-        for (int u : g[i]) {
-            max_dep = 0;
-            std::fill(cnt.begin(), cnt.end(), 0);
-
-            dfs(u, i, 1);
-
-            for (int j = 1; j <= max_dep; j++) {
-                ans += f1[j] * cnt[j];
-                f1[j] += f2[j] * cnt[j];
-                f2[j] += cnt[j];
-            }
-        }
-    }
-
-    cout << ans << endl;
-
-    return 0;
-}

Luogu/P3565/P3565.cpp

@@ -1,64 +0,0 @@
-#include <iostream>
-#include <algorithm>
-#include <array>
-#include <vector>
-
-using std::cin;
-using std::cout;
-const char endl = '\n';
-
-const int N = 5005;
-
-int n, max_dep;
-long long ans;
-std::vector<int> g[N];
-std::array<int, N> f1, f2, cnt;
-
-void dfs(int u, int f, int d) {
-    cnt[d]++;
-    max_dep = std::max(max_dep, d);
-
-    for (int v : g[u]) {
-        if (v == f) continue;
-
-        dfs(v, u, d + 1);
-    }
-}
-
-int main() {
-    std::ios::sync_with_stdio(false);
-    cin.tie(nullptr);
-
-    cin >> n;
-
-    for (int i = 1, u, v; i < n; i++) {
-        cin >> u >> v;
-
-        g[u].emplace_back(v);
-        g[v].emplace_back(u);
-    }
-
-    dfs(1, 0, 1);
-
-    for (int i = 1; i <= n; i++) {
-        std::fill(f1.begin(), f1.end(), 0);
-        std::fill(f2.begin(), f2.end(), 0);
-
-        for (int u : g[i]) {
-            max_dep = 0;
-            std::fill(cnt.begin(), cnt.end(), 0);
-
-            dfs(u, i, 1);
-
-            for (int j = 1; j <= max_dep; j++) {
-                ans += f1[j] * cnt[j];
-                f1[j] += f2[j] * cnt[j];
-                f2[j] += cnt[j];
-            }
-        }
-    }
-
-    cout << ans << endl;
-
-    return 0;
-}

S2OJ/1538/1538.cpp

@@ -1,68 +0,0 @@
-#include <iostream>
-#include <algorithm>
-#include <array>
-#include <vector>
-
-using std::cin;
-using std::cout;
-const char endl = '\n';
-
-const int N = 3005;
-
-int n, root, max_dep;
-long long ans;
-std::vector<int> g[N];
-std::array<int, N> f1, f2, cnt;
-
-void dfs(int u, int f, int d) {
-    cnt[d]++;
-    max_dep = std::max(max_dep, d);
-
-    for (int v : g[u]) {
-        if (v == f) continue;
-
-        dfs(v, u, d + 1);
-    }
-}
-
-int main() {
-    std::ios::sync_with_stdio(false);
-    cin.tie(nullptr);
-
-    cin >> n;
-
-    for (int i = 1, x; i <= n; i++) {
-        cin >> x;
-
-        if (x) {
-            g[x].emplace_back(i);
-            g[i].emplace_back(x);
-        } else {
-            root = i;
-        }
-    }
-
-    dfs(root, 0, 1);
-
-    for (int i = 1; i <= n; i++) {
-        std::fill(f1.begin(), f1.end(), 0);
-        std::fill(f2.begin(), f2.end(), 0);
-
-        for (int u : g[i]) {
-            max_dep = 0;
-            std::fill(cnt.begin(), cnt.end(), 0);
-
-            dfs(u, i, 1);
-
-            for (int j = 1; j <= max_dep; j++) {
-                ans += f1[j] * cnt[j];
-                f1[j] += f2[j] * cnt[j];
-                f2[j] += cnt[j];
-            }
-        }
-    }
-
-    cout << ans << endl;
-
-    return 0;
-}