2069. [POI2004] ZAW

https://hydro.ac/d/bzoj/record/63b77e80eae63550a15ba66c

BZOJ/2069/2069.cpp

@@ -0,0 +1,96 @@
+#include <iostream>
+#include <algorithm>
+#include <functional>
+#include <queue>
+#include <tuple>
+#include <utility>
+#include <vector>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int INF = 0x3f3f3f3f;
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    int n, m, ans = INF;
+
+    cin >> n >> m;
+
+    int s = 0, t = n + 1, size = t + 1;
+    std::vector<std::tuple<int, int, int, int>> edges(m);
+
+    for (auto& e : edges) {
+        cin >> std::get<0>(e) >> std::get<1>(e) >> std::get<2>(e) >> std::get<3>(e);
+    }
+
+    for (int k = 0; k <= std::__lg(n); k++) {
+        std::vector<std::vector<std::pair<int, int>>> g(size);
+
+        for (auto& e : edges) {
+            int u, v, a, b;
+
+            std::tie(u, v, a, b) = e;
+
+            if (u == 1) {
+                if (v & (1 << k)) {
+                    g[s].emplace_back(v, a);
+                    g[v].emplace_back(s, b);
+                } else {
+                    g[v].emplace_back(t, b);
+                    g[t].emplace_back(v, a);
+                }
+            } else if (v == 1) {
+                if (u & (1 << k)) {
+                    g[s].emplace_back(u, b);
+                    g[u].emplace_back(s, a);
+                } else {
+                    g[u].emplace_back(t, a);
+                    g[t].emplace_back(u, b);
+                }
+            } else {
+                g[u].emplace_back(v, a);
+                g[v].emplace_back(u, b);
+            }
+        }
+
+        std::function<int(int, int)> dijkstra = [&](int s, int t) -> int {
+            std::vector<int> dist(size, INF);
+            std::vector<bool> vis(size);
+            std::priority_queue<std::pair<int, int>, std::vector<std::pair<int, int>>, std::greater<>> q;
+
+            q.emplace(0, s);
+            dist[s] = 0;
+
+            while (!q.empty()) {
+                int u = q.top().second;
+                q.pop();
+
+                if (vis[u]) continue;
+                vis[u] = true;
+
+                for (auto e : g[u]) {
+                    int v = e.first,
+                        w = e.second;
+
+                    if (dist[v] > dist[u] + w) {
+                        dist[v] = dist[u] + w;
+
+                        q.emplace(dist[v], v);
+                    }
+                }
+            }
+
+            return dist[t];
+        };
+
+        ans = std::min({ans, dijkstra(s, t), dijkstra(t, s)});
+    }
+
+    cout << ans << endl;
+
+    return 0;
+}