1 #include<bits/stdc++.h>
2 using namespace std;
3 #define INF 0x3f3f3f3f
4 #define M(a, b) memset(a, b, sizeof(a))
5 const int N = 1e3 + 5;
6 struct Edge {
7 int from, to, cap, flow, cost;
8 };
9
10 struct MCMF {
11 int n, m;
12 vector<Edge> edges;
13 vector<int> G[N];
14 int d[N], inq[N], p[N], a[N];
15
16 void init(int n) {
17 this->n = n;
18 for (int i = 0; i < n; ++i) G[i].clear();
19 edges.clear();
20 }
21
22 void AddEdge(int from, int to, int cap, int cost) {
23 edges.push_back((Edge){from, to, cap, 0, cost});
24 edges.push_back((Edge){to, from, 0, 0, -cost});
25 m = edges.size();
26 G[from].push_back(m-2); G[to].push_back(m-1);
27 }
28
29 bool spfa(int s, int t, int &flow, int &cost) {
30 M(inq, 0); M(d, INF);
31 d[s] = 0; inq[s] = 1; p[s] = 0; a[s] = INF;
32 queue<int> q;
33 q.push(s);
34 while (!q.empty()) {
35 int x = q.front(); q.pop();
36 inq[x] = 0;
37 for (int i = 0; i < G[x].size(); ++i) {
38 Edge &e = edges[G[x][i]];
39 if (d[e.to] > d[x] + e.cost && e.cap > e.flow) {
40 d[e.to] = d[x] + e.cost;
41 p[e.to] = G[x][i];
42 a[e.to] = min(a[x], e.cap-e.flow);
43 if (inq[e.to]) continue;
44 q.push(e.to); inq[e.to] = 1;
45 }
46 }
47 }
48 if (d[t] == INF) return false;
49 flow += a[t];
50 cost += d[t] * a[t];
51 int u = t;
52 while (u != s) {
53 edges[p[u]].flow += a[t];
54 edges[p[u]^1].flow -= a[t];
55 u = edges[p[u]].from;
56 }
57 return true;
58 }
59
60 int Mincost(int s, int t) {
61 int flow = 0, cost = 0;
62 while (spfa(s, t, flow, cost));
63 return cost;
64 }
65
66 };
