diff options
Diffstat (limited to 'graph/hopcroftKarp.cpp')
| -rw-r--r-- | graph/hopcroftKarp.cpp | 47 |
1 files changed, 0 insertions, 47 deletions
diff --git a/graph/hopcroftKarp.cpp b/graph/hopcroftKarp.cpp deleted file mode 100644 index c1f5d1c..0000000 --- a/graph/hopcroftKarp.cpp +++ /dev/null @@ -1,47 +0,0 @@ -vector<vector<int>> adj; -// pairs ist der gematchte Knoten oder -1 -vector<int> pairs, dist, ptr; - -bool bfs(int l) { - queue<int> q; - for(int v = 0; v < l; v++) { - if (pairs[v] < 0) {dist[v] = 0; q.push(v);} - else dist[v] = -1; - } - bool exist = false; - while(!q.empty()) { - int v = q.front(); q.pop(); - for (int u : adj[v]) { - if (pairs[u] < 0) {exist = true; continue;} - if (dist[pairs[u]] < 0) { - dist[pairs[u]] = dist[v] + 1; - q.push(pairs[u]); - }}} - return exist; -} - -bool dfs(int v) { - for (; ptr[v] < sz(adj[v]); ptr[v]++) { - int u = adj[v][ptr[v]]; - if (pairs[u] < 0 || - (dist[pairs[u]] > dist[v] && dfs(pairs[u]))) { - pairs[u] = v; pairs[v] = u; - return true; - }} - return false; -} - -int hopcroft_karp(int l) { // l = #Knoten links - int ans = 0; - pairs.assign(sz(adj), -1); - dist.resize(l); - // Greedy Matching, optionale Beschleunigung. - for (int v = 0; v < l; v++) for (int u : adj[v]) - if (pairs[u] < 0) {pairs[u] = v; pairs[v] = u; ans++; break;} - while(bfs(l)) { - ptr.assign(l, 0); - for(int v = 0; v < l; v++) { - if (pairs[v] < 0) ans += dfs(v); - }} - return ans; -} |
