匈牙利算法（附UOJ - 78 二分图最大匹配代码）

Hungarian-Algorithm.cpp

@@ -0,0 +1,73 @@
+#include <cstdio>
+#include <cstring>
+
+#define VERTEX_COUNT 1010
+#define EDGE_COUNT 250010
+
+using namespace std;
+
+struct vertex
+{
+	int first, mv;
+}V[VERTEX_COUNT];
+
+struct edge
+{
+	int endp, next;
+}E[EDGE_COUNT];
+
+int nl, nr, iec, ec = 2;
+bool vis[VERTEX_COUNT];
+
+inline void add_edge(int u, int v)
+{
+	E[ec].next = V[u].first;
+	V[u].first = ec;
+	E[ec].endp = v;
+	ec++;
+}
+
+bool dfs(int u)
+{
+	if (vis[u] == true) return false;
+	vis[u] = true;
+	for (int cur = V[u].first; cur != 0; cur = E[cur].next)
+	{
+		if (V[u].mv != E[cur].endp && (V[E[cur].endp].mv == 0 || dfs(V[E[cur].endp].mv) == true))
+		{
+			V[u].mv = E[cur].endp;
+			V[E[cur].endp].mv = u;
+			return true;
+		}
+	}
+	return false;
+}
+
+int match()
+{
+	int res = 0;
+	for (int i = 1; i <= nl; i++)
+	{
+		memset(vis, false, sizeof(vis));
+		res += (int)dfs(i);
+	}
+	return res;
+}
+
+int main()
+{
+	int u, v;
+	scanf("%d%d%d", &nl, &nr, &iec);
+	for (int i = 0; i < iec; i++)
+	{
+		scanf("%d%d", &u, &v);
+		add_edge(u, v + nl);
+	}
+	printf("%d\n", match());
+	for (int i = 1; i <= nl; i++)
+	{
+		if (V[i].mv != 0) printf("%d ", V[i].mv - nl);
+		else printf("0 ");
+	}
+	return 0;
+}