POJ

PKU/2781 - The mysterious X network.cpp

@@ -0,0 +1,57 @@
+#include <cstdio>
+#include <cstring>
+
+using namespace std;
+
+#define MAXV 100000
+#define MAXE 10000000
+
+int E = 0,to[MAXE],next[MAXE],last[MAXV];
+int Q[MAXV],head,tail,dist[MAXV];
+
+void add_edge(int u, int v){
+    to[E] = v; next[E] = last[u]; last[u] = E++;
+}
+
+int main(){
+    int N;
+
+    scanf("%d",&N);
+
+    memset(last,-1,sizeof last);
+
+    for(int i = 0,u,v,m;i < N;++i){
+        scanf("%d %d",&u,&m);
+
+        for(int j = 0;j < m;++j){
+            scanf("%d",&v);
+            add_edge(u,v);
+        }
+    }
+
+    head = tail = 0;
+    memset(dist,-1,sizeof dist);
+
+    int s,t;
+    scanf("%d %d",&s,&t);
+
+    Q[tail++] = s;
+    dist[s] = 0;
+
+    while(head < tail){
+        int cur = Q[head++];
+
+        for(int e = last[cur],x;e != -1;e = next[e]){
+            x = to[e];
+
+            if(dist[x] == -1){
+                Q[tail++] = x;
+                dist[x] = 1 + dist[cur];
+            }
+        }
+    }
+
+    printf("%d %d %d\n",s,t,dist[t] - 1);
+
+    return 0;
+}

PKU/2784 - Buy or Build.cpp

@@ -0,0 +1,84 @@
+#include <cstdio>
+#include <cstring>
+#include <algorithm>
+
+using namespace std;
+
+int sz[8],cost[8],L[8][1000];
+int x[1000],y[1000],parent[1001];
+
+int Find(int x){
+    if(parent[x] != x) parent[x] = Find(parent[x]);
+    return parent[x];
+}
+
+void Union(int x, int y){
+    x = Find(x); y = Find(y);
+    parent[x] = y;
+}
+
+struct edge{
+    int u,v,w;
+
+    edge(){}
+    edge(int _u, int _v, int _w) : u(_u), v(_v), w(_w){}
+
+    bool operator < (edge X)const{
+        return w < X.w;
+    }
+}e[1000000];
+
+int main(){
+    int n,m;
+
+    scanf("%d %d",&n,&m);
+
+    for(int i = 0;i < m;++i){
+        scanf("%d %d",&sz[i],&cost[i]);
+
+        for(int j = 0;j < sz[i];++j)
+            scanf("%d",&L[i][j]);
+    }
+
+    for(int i = 0;i < n;++i)
+        scanf("%d %d",&x[i],&y[i]);
+
+    int E = 0;
+
+    for(int i = 0;i < n;++i)
+        for(int j = i + 1;j < n;++j)
+            e[E++] = edge(i + 1,j + 1,(x[i] - x[j]) * (x[i] - x[j]) + (y[i] - y[j]) * (y[i] - y[j]));
+
+    sort(e,e + E);
+
+    long long ans = (1LL << 60);
+
+    for(int mask = 0;mask < (1 << m);++mask){
+        long long aux = 0;
+
+        for(int i = 1;i <= n;++i)
+            parent[i] = i;
+
+        for(int i = 0;i < m;++i){
+            if(mask & (1 << i)){
+                aux += cost[i];
+
+                for(int j = sz[i] - 1;j > 0;--j)
+                    Union(L[i][j],L[i][0]);
+            }
+        }
+
+        for(int i = 0;i < E;++i){
+            if(Find(e[i].u) != Find(e[i].v)){
+                aux += e[i].w;
+                Union(e[i].u,e[i].v);
+            }
+        }
+
+        ans = min(ans,aux);
+    }
+
+    printf("%d\n",ans);
+
+    return 0;
+}