1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
| const double eps=1e-8;
struct MCMF{
static const int maxn=200,maxm=40000;
struct star{int v,nex;double c,w;} edge[maxm<<1];
int head[maxn],cnt,n;
int inq[maxn],pre[maxn];
double dist[maxn];
void ini(int n){
cnt=-1;this->n=n;
for(int i=0;i<=n;i++) head[i]=-1;
}
void add_star(int u, int v, double c, double w){
edge[++cnt]=star{v,head[u],c, w}; head[u]=cnt;
edge[++cnt]=star{u,head[v],0,-w}; head[v]=cnt;
}
void minCostMaxFlow(int s, int t,double&flow,double&cost){
flow=cost=0;
while(true){
for(int i=0;i<=n;i++) dist[i]=1e9;
queue<int>que; que.push(s);
inq[s]=1; dist[s]=0;
while(!que.empty()){
int u=que.front();
que.pop(); inq[u]=0;
for(int i=head[u];~i;i=edge[i].nex){
int v=edge[i].v;
double c=edge[i].c,w=edge[i].w;
if(c>eps&&dist[v]>dist[u]+w+eps){
dist[v]=dist[u]+w;
pre[v]=i;
if(!inq[v]) que.push(v);
inq[v]=1;
}
}
}
if(dist[t]==1e9) return ;
double addf=1e9;
for(int x=t;x!=s;x=edge[pre[x]^1].v) addf=min(addf,edge[pre[x]].c);
for(int x=t;x!=s;x=edge[pre[x]^1].v){
edge[pre[x]].c-=addf;
edge[pre[x]^1].c+=addf;
}
flow+=addf;
cost+=dist[t]*addf;
}
}
} g;
|
