4380. [POI2015]Myjnie

https://hydro.ac/d/bzoj/record/6322a2ebbdf9bc31d1605b23

BZOJ/4380/4380.cpp

@@ -0,0 +1,111 @@
+#include <iostream>
+#include <algorithm>
+#include <numeric>
+#include <tuple>
+#include <vector>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    int n, m;
+
+    cin >> n >> m;
+
+    std::vector<std::tuple<int, int, int>> data(m);
+    std::vector<int> nums;
+
+    for (auto& e : data) {
+        int a, b, c;
+
+        cin >> a >> b >> c;
+
+        e = std::make_tuple(a - 1, b - 1, c);
+        nums.push_back(c);
+    }
+
+    std::sort(nums.begin(), nums.end());
+    nums.erase(std::unique(nums.begin(), nums.end()), nums.end());
+
+    for (auto& e : data) {
+        std::get<2>(e) = std::lower_bound(nums.begin(), nums.end(), std::get<2>(e)) - nums.begin();
+    }
+
+    std::vector<std::vector<int>> g(n, std::vector<int>(nums.size(), 0));
+    std::vector<std::vector<std::vector<int>>>
+        f(n, std::vector<std::vector<int>>(n, std::vector<int>(nums.size(), 0))),
+        pos(n, std::vector<std::vector<int>>(n, std::vector<int>(nums.size(), 0))),
+        pre(n, std::vector<std::vector<int>>(n, std::vector<int>(nums.size(), 0)));
+
+    for (int len = 1; len <= n; len++) {
+        for (int l = 0, r = l + len - 1; r < n; l++, r++) {
+            std::for_each(g.begin() + l, g.begin() + r + 1, [&](auto& v) {
+                std::fill(v.begin(), v.end(), 0);
+            });
+
+            for (const auto& e : data) {
+                int a, b, c;
+                std::tie(a, b, c) = e;
+
+                if (l <= a && b <= r) {
+                    std::for_each(g.begin() + a, g.begin() + b + 1, [&](auto& v) { v[c]++; });
+                }
+            }
+
+            std::for_each(g.begin() + l, g.begin() + r + 1, [&](auto& v) {
+                std::partial_sum(v.rbegin(), v.rend(), v.rbegin());
+            });
+
+            for (int i = nums.size() - 1; i >= 0; i--) {
+                int max = 0;
+                for (int j = l; j <= r; j++) {
+                    int t = (j > 0 ? f[l][j - 1][i] : 0)
+                          + (j + 1 < n ? f[j + 1][r][i] : 0)
+                          + g[j][i] * nums[i];
+
+                    if (max <= t) {
+                        max = t;
+                        pos[l][r][i] = j;
+                    }
+                }
+
+                if (i + 1 == nums.size() || f[l][r][i + 1] <= max) {
+                    f[l][r][i] = max;
+                    pre[l][r][i] = i;
+                } else {
+                    f[l][r][i] = f[l][r][i + 1];
+                    pre[l][r][i] = pre[l][r][i + 1];
+                }
+            }
+        }
+    }
+
+    cout << f[0][n - 1][0] << endl;
+
+    std::vector<int> ans(n);
+
+    auto dfs = [&](int l, int r, int k, auto&& dfs) -> void {
+        if (l > r) return;
+
+        int p = pos[l][r][k = pre[l][r][k]];
+
+        ans[p] = nums[k];
+
+        dfs(l, p - 1, k, dfs);
+        dfs(p + 1, r, k, dfs);
+    };
+
+    dfs(0, n - 1, 0, dfs);
+
+    for (const int& x : ans) {
+        cout << x << ' ';
+    }
+
+    cout << endl;
+
+    return 0;
+}