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OI-codes/BZOJ/2069/2069.cpp

97 lines
2.4 KiB
C++

#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;
}