| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 911119 | NoLove | Commuter Pass (JOI18_commuter_pass) | C++14 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
typedef long long ll;
using namespace std;
vector<pair<ll, ll>> graph[100001];
ll du[100001], dv[100001], ds[100001], dp[2][100001], ans;
bool visited[100001];
void dijkstra1(ll start, ll arr[]) {
fill(visited, visited + 100001, false);
priority_queue<pair<ll, ll>> pq;
pq.push({0, start});
while (!pq.empty()) {
ll c, node;
tie(c, node) = pq.top();
pq.pop();
if (!visited[node]) {
arr[node] = -c;
visited[node] = true;
for (auto &i : graph[node]) pq.push({c - i.second, i.first});
}
}
}
void dijkstra2(ll start, ll end) {
fill(dp[0], dp[0] + 100001, LLONG_MAX / 2);
fill(dp[1], dp[1] + 100001, LLONG_MAX / 2);
fill(visited, visited + 100001, false);
priority_queue<pair<ll, pair<ll, ll>>> pq;
pq.push({0, {start, 0}});
dp[0][0] = dp[1][0] = LLONG_MAX / 2;
db(start, end)
while (!pq.empty()) {
ll c, node, par;
pair<ll, ll> p;
auto x = pq.top();
tie(c, p) = pq.top();
tie(node, par) = p;
pq.pop();
if (!visited[node]) {
visited[node] = true;
ds[node] = -c;
dp[0][node] = min(du[node], dp[0][par]);
dp[1][node] = min(dv[node], dp[1][par]);
// db(x, dp[0][node], dp[1][node])
for (auto i : graph[node]) pq.push({c - i.second, {i.first, node}});
} else if (-c == ds[node]) {
// if (min(du[node], dp[0][par]) + min(dv[node], dp[1][par]) <=
// dp[0][node] + dp[1][node]) {
dp[0][node] = min(du[node], dp[0][par]);
dp[1][node] = min(dv[node], dp[1][par]);
// }
}
}
// db(dp[0][end], dp[1][end])
ans = min(ans, dp[0][end] + dp[1][end]);
}
int main() {
if (fopen("hi.inp", "r")) {
freopen("hi.inp", "r", stdin);
// freopen("hi.out", "w", stdout);
}
iostream::sync_with_stdio(false);
cin.tie(0);
ll n, m, s, t, u, v;
cin >> n >> m >> s >> t >> u >> v;
for (int i = 0; i < m; i++) {
ll a, b, c;
cin >> a >> b >> c;
graph[a].push_back({b, c});
graph[b].push_back({a, c});
}
dijkstra1(u, du);
dijkstra1(v, dv);
ans = du[v];
dijkstra2(s, t);
// dijkstra2(t, s);
cout << ans << '\n';
return 0;
}