mirror of
https://git.sb/baoshuo/OI-codes.git
synced 2024-11-23 20:28:48 +00:00
parent
4b559955d0
commit
33ce941813
90
Luogu/P4878/P4878.cpp
Normal file
90
Luogu/P4878/P4878.cpp
Normal file
@ -0,0 +1,90 @@
|
||||
#include <iostream>
|
||||
#include <algorithm>
|
||||
#include <iterator>
|
||||
#include <queue>
|
||||
#include <vector>
|
||||
|
||||
using std::cin;
|
||||
using std::cout;
|
||||
const char endl = '\n';
|
||||
|
||||
const int N = 1005;
|
||||
const int INF = 0x3f3f3f3f;
|
||||
|
||||
int n, ml, md, cnt[N], dist[N];
|
||||
std::vector<std::pair<int, int>> g[N];
|
||||
bool vis[N];
|
||||
|
||||
bool spfa(int s) {
|
||||
std::fill(std::begin(cnt), std::end(cnt), 0);
|
||||
std::fill(std::begin(vis), std::end(vis), false);
|
||||
std::fill(std::begin(dist), std::end(dist), INF);
|
||||
|
||||
std::queue<int> q;
|
||||
|
||||
q.emplace(s);
|
||||
dist[s] = 0;
|
||||
vis[s] = true;
|
||||
|
||||
while (!q.empty()) {
|
||||
int u = q.front();
|
||||
q.pop();
|
||||
|
||||
vis[u] = false;
|
||||
|
||||
for (auto e : g[u]) {
|
||||
int v = e.first,
|
||||
w = e.second;
|
||||
|
||||
if (dist[v] > dist[u] + w) {
|
||||
dist[v] = dist[u] + w;
|
||||
|
||||
if (!vis[v]) {
|
||||
cnt[v] = cnt[u] + 1;
|
||||
|
||||
if (cnt[v] >= n) return false;
|
||||
|
||||
vis[v] = true;
|
||||
q.emplace(v);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
int main() {
|
||||
std::ios::sync_with_stdio(false);
|
||||
cin.tie(nullptr);
|
||||
|
||||
cin >> n >> ml >> md;
|
||||
|
||||
for (int i = 1; i <= n; i++) {
|
||||
g[0].emplace_back(i, 0);
|
||||
}
|
||||
|
||||
for (int i = 2; i <= n; i++) {
|
||||
g[i].emplace_back(i - 1, 0);
|
||||
}
|
||||
|
||||
for (int i = 1, a, b, c; i <= ml; i++) {
|
||||
cin >> a >> b >> c;
|
||||
|
||||
g[a].emplace_back(b, c);
|
||||
}
|
||||
|
||||
for (int i = 1, a, b, c; i <= md; i++) {
|
||||
cin >> a >> b >> c;
|
||||
|
||||
g[b].emplace_back(a, -c);
|
||||
}
|
||||
|
||||
if (spfa(0) && spfa(1)) {
|
||||
cout << (dist[n] == INF ? -2 : dist[n]) << endl;
|
||||
} else {
|
||||
cout << -1 << endl;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
BIN
Luogu/P4878/data/P4878_14.in
(Stored with Git LFS)
Normal file
BIN
Luogu/P4878/data/P4878_14.in
(Stored with Git LFS)
Normal file
Binary file not shown.
BIN
Luogu/P4878/data/P4878_14.out
(Stored with Git LFS)
Normal file
BIN
Luogu/P4878/data/P4878_14.out
(Stored with Git LFS)
Normal file
Binary file not shown.
Loading…
Reference in New Issue
Block a user