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Update mcmf.cpp to simplify updates to total_cost #112

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Update mcmf.cpp to simplify updates to total_cost #112

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5 changes: 3 additions & 2 deletions ch9/mcmf.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -51,7 +51,6 @@ class min_cost_max_flow {
auto &[v, cap, flow, cost] = EL[AL[u][i]];
if (!vis[v] && d[v] == d[u]+cost) { // in current layer graph
if (ll pushed = DFS(v, t, min(f, cap-flow))) {
total_cost += pushed * cost;
flow += pushed;
auto &[rv, rcap, rflow, rcost] = EL[AL[u][i]^1]; // back edge
rflow -= pushed;
Expand Down Expand Up @@ -86,8 +85,10 @@ class min_cost_max_flow {
ll mf = 0; // mf stands for max_flow
while (SPFA(s, t)) { // an O(V^2*E) algorithm
last.assign(V, 0); // important speedup
while (ll f = DFS(s, t)) // exhaust blocking flow
while (ll f = DFS(s, t)) { // exhaust blocking flow
mf += f;
total_cost += f * d[t];
}
}
return {mf, total_cost};
}
Expand Down