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
52
53
54
55
56
57
58
59
|
double costs[N_LEFT][N_RIGHT];
// Es muss l<=r sein! (sonst Endlosschleife)
double match(int l, int r) {
vector<double> lx(l), ly(r);
//xy is matching from l->r, yx from r->l, or -1
vector<int> xy(l, -1), yx(r, -1), augmenting(r);
vector<bool> s(l);
vector<pair<double, int>> slack(r);
for (int x = 0; x < l; x++)
lx[x] = *max_element(costs[x], costs[x] + r);
for (int root = 0; root < l; root++) {
augmenting.assign(r, -1);
s.assign(l, false);
s[root] = true;
for (int y = 0; y < r; y++) {
slack[y] = {lx[root] + ly[y] - costs[root][y], root};
}
int y = -1;
while (true) {
double delta = INF;
int x = -1;
for (int yy = 0; yy < r; yy++) {
if (augmenting[yy] < 0) {
if (slack[yy].first < delta) {
delta = slack[yy].first;
x = slack[yy].second;
y = yy;
}}}
if (delta > 0) {
for (int x = 0; x < l; x++) if (s[x]) lx[x] -= delta;
for (int y = 0; y < r; y++) {
if (augmenting[y] >= 0) ly[y] += delta;
else slack[y].first -= delta;
}}
augmenting[y] = x;
x = yx[y];
if (x == -1) break;
s[x] = true;
for (int y = 0; y < r; y++) {
if (augmenting[y] < 0) {
double alt = lx[x] + ly[y] - costs[x][y];
if (slack[y].first > alt) {
slack[y] = {alt, x};
}}}}
while (y >= 0) {
// Jede Iteration vergrößert Matching um 1
// (können 0-Kanten sein!)
int x = augmenting[y];
int prec = xy[x];
yx[y] = x;
xy[x] = y;
y = prec;
}}
// Wert des Matchings
return accumulate(all(lx), 0.0) +
accumulate(all(ly), 0.0);
}
|
