shorten hungarian

1 files changed, 14 insertions, 23 deletions

diff --git a/graph/maxWeightBipartiteMatching.cpp b/graph/maxWeightBipartiteMatching.cpp
index 5eda19b..a2b0a80 100644
--- a/graph/maxWeightBipartiteMatching.cpp
+++ b/graph/maxWeightBipartiteMatching.cpp
@@ -4,15 +4,14 @@ double costs[N_LEFT][N_RIGHT];
 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<int> xy(l, -1), yx(r, -1);
 	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);
+		vector<int> aug(r, -1);
+		vector<bool> s(l);
 		s[root] = true;
 		for (int y = 0; y < r; y++) {
 			slack[y] = {lx[root] + ly[y] - costs[root][y], root};
@@ -22,38 +21,30 @@ double match(int l, int r) {
 			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 (aug[yy] < 0 && slack[yy].first < delta) {
+					tie(delta, x) = slack[yy];
+					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;
+					if (aug[y] >= 0) ly[y] += delta;
 					else slack[y].first -= delta;
 			}}
-			augmenting[y] = x;
+			aug[y] = x;
 			x = yx[y];
-			if (x == -1) break;
+			if (x < 0) break;
 			s[x] = true;
 			for (int y = 0; y < r; y++) {
-				if (augmenting[y] < 0) {
+				if (aug[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;
+			yx[y] = aug[y];
+			swap(y, xy[aug[y]]);
 	}}
-	// Wert des Matchings
 	return accumulate(all(lx), 0.0) +
-	       accumulate(all(ly), 0.0);
+	       accumulate(all(ly), 0.0); // Wert des Matchings
 }