subcrip
/
cp-templates
1
0
Fork 0
Code

Add graph/examples/active_flow_with_demands.cc 

Signed-off-by: subcrip <contact@subc.rip>
This commit is contained in:
subcrip 2024-05-19 14:37:06 +08:00
parent b2ee09573e
commit ed19bc6a85
1 changed files with 31 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
graph/examples/active_flow_with_demands.cc Normal file
View File

@ -0,0 +1,31 @@
struct dinic {
// ...
};
void solve() {
read(int, n, m, s, t);
dinic net(n + 1);
int S = 0, T = n + 1;
vector<int> init(n + 1);
for (int i = 0 ;i < m; ++i) {
read(int, u, v, lower, upper);
init[v] += lower;
init[u] -= lower;
net.add_edge(u, v, upper - lower);
}
int sum = 0;
for (int i =1; i <= n; ++i) {
if (init[i] > 0) {
net.add_edge(S, i, init[i]);
sum += init[i];
} else if (init[i] < 0) {
net.add_edge(i, T, -init[i]);
}
}
net.add_edge(t, s, INF); // WARN: s->t is wrong
if (sum != net.run(S, T)) {
cout << "please go home to sleep\n";
} else {
cout << net.run(s, t) << '\n';
}
}