rng_58_dinic

grid move/grid_move_bfs_pq.cpp

@@ -106,7 +106,7 @@ int bfs()
 		for (int i = 0; i < 4; i++)
 		{
 			Point v = u + dir[i];
-			if (out(v) || grid[v.x][v.y] == '#')
+			if (out(v) || grid[v.x][v.y] != '.')
 			{
 				continue;
 			}

network flow/rng_58_dinic.cpp

@@ -0,0 +1,59 @@
+#define REP(i,n) for((i)=0;(i)<(int)(n);(i)++)
+#define snuke(c,itr) for(__typeof((c).begin()) itr=(c).begin();itr!=(c).end();itr++)
+
+typedef int F;
+#define F_INF (1<<29)
+#define MAXV 1000
+#define MAXE 1000 // E*2!
+
+F cap[MAXE],flow[MAXE];
+int to[MAXE],_prev[MAXE],last[MAXV],used[MAXV],level[MAXV];
+
+struct MaxFlow{
+    int V,E;
+
+    MaxFlow(int n){
+        int i;
+        V = n; E = 0;
+        REP(i,V) last[i] = -1;
+    }
+
+    void add_edge(int x, int y, F f){
+        cap[E] = f; flow[E] = 0; to[E] = y; _prev[E] = last[x]; last[x] = E; E++;
+        cap[E] = 0; flow[E] = 0; to[E] = x; _prev[E] = last[y]; last[y] = E; E++;
+    }
+
+    bool bfs(int s, int t){
+        int i;
+        REP(i,V) level[i] = -1;
+        queue <int> q;
+        q.push(s); level[s] = 0;
+        while(!q.empty()){
+            int x = q.front(); q.pop();
+            for(i=last[x];i>=0;i=_prev[i]) if(level[to[i]] == -1 && cap[i] > flow[i]) {q.push(to[i]); level[to[i]] = level[x] + 1;}
+        }
+        return (level[t] != -1);
+    }
+
+    F dfs(int v, int t, F f){
+        int i;
+        if(v == t) return f;
+        for(i=used[v];i>=0;used[v]=i=_prev[i]) if(level[to[i]] > level[v] && cap[i] > flow[i]){
+            F tmp = dfs(to[i],t,min(f,cap[i]-flow[i]));
+            if(tmp > 0) {flow[i] += tmp; flow[i^1] -= tmp; return tmp;}
+        }
+        return 0;
+    }
+
+    F maxflow(int s, int t){
+        int i;
+        while(bfs(s,t)){
+            REP(i,V) used[i] = last[i];
+            while(dfs(s,t,F_INF) != 0);
+        }
+        F ans = 0;
+        for(i=last[s];i>=0;i=_prev[i]) ans += flow[i];
+        return ans;
+    }
+
+};