First problem uploaded here.

I am stupid, I made a struct that ordenates everything
into a different way, but then I forgot to change the
variables on the dijkstra loop to the correct order and
ended up screwing everything...

At least I'm sure I won't be doing this mistake again in
the future.
This commit is contained in:
Segcolt 2024-09-24 09:41:49 -03:00
parent 7ab6d7a33c
commit 0040981432
2 changed files with 144 additions and 0 deletions

2
.gitignore vendored
View File

@ -32,3 +32,5 @@
*.out *.out
*.app *.app
# Ignore testcases files from competitest
*.testcases

View File

@ -0,0 +1,142 @@
/* Problem URL: https://cses.fi/problemset/task/1195 */
#include <bits/stdc++.h>
using namespace std;
#define V vector
#define rmin(a, b) a = min(a, b)
#define rmax(a, b) a = max(a, b)
#define rep(i, lim) for (size_t i = 0; i < (lim); i++)
#define nrep(i, s, lim) for (size_t i = s; i < (lim); i++)
#define repv(i, v) for (auto &i : (v))
#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
#define sortv(v) sort(v.begin(), v.end())
#define all(v) (v).begin(), (v).end()
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vvvvi = vector<vvvi>;
using ll = long long;
using vl = vector<ll>;
using vvl = vector<vl>;
using vvvl = vector<vvl>;
using vvvvl = vector<vvvl>;
template<class v>
auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
os << vec[0];
for (size_t i = 1; i < vec.size(); i++) {
os << ' ' << vec[i];
}
os << '\n';
return os;
}
template<class v>
auto operator>>(istream &is, vector<v> &vec)->istream& {
for (auto &i : vec) {
is >> i;
}
return is;
}
template<class v>
auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
for (auto &i : vec) {
os << i[0];
for (size_t j = 1; j < i.size(); j++) {
os << ' ' << i[j];
}
os << '\n';
}
return os;
}
template<class v>
auto operator>>(istream &is, vector<vector<v>> &vec)->istream& {
for (auto &i : vec) {
for (auto &j : i) {
is >> j;
}
}
return is;
}
struct node {
public:
int no;
ll cost;
int used;
node(int no, long long cost, int used) : no(no), cost(cost), used(used) {}
auto operator<(node &n) const->bool {
return cost < n.cost;
}
auto operator>(node &n) const->bool {
return cost > n.cost;
}
};
vvl dist;
V<V<pair<int, ll>>> graph;
long long dijkstra(int n)
{
priority_queue<node, V<node>, greater<>> pq;
pq.emplace(0, 0, 0);
dist[0][0] = 0;
dist[0][1] = 0;
while (!pq.empty()) {
auto [v, u, b] = pq.top(); pq.pop();
if (dist[v][b] < u) {
continue;
}
for (auto [n, c] : graph[v]) {
if (u + c < dist[n][b]) {
dist[n][b] = u + c;
pq.emplace(n, dist[n][b], b);
}
if (b == 0 && u + (c / 2) < dist[n][1]) {
dist[n][1] = u + (c / 2);
pq.emplace(n, dist[n][1], 1) ;
}
}
}
return min(dist[n - 1][0], dist[n - 1][1]);
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n, m;
cin >> n >> m;
dist.assign(n, vl(2, INT64_MAX));
graph.resize(n);
while (m--) {
long long a, b, c;
cin >> a >> b >> c;
a--, b--;
graph[a].emplace_back(b, c);
}
cout << dijkstra(n) << '\n';
return 0;
}