Create 4444_woshinannan741.cpp

From http://blog.csdn.net/woshinannan741/article/details/52235990

SCU/4444_woshinannan741.cpp

@@ -0,0 +1,102 @@
+#include<cstdio>
+#include<cstring>
+#include<queue>
+#include<set>
+#include<algorithm>
+using namespace std;
+const int MAXN = 5e5+5;
+const int INF  = 0x3f3f3f3f;
+typedef long long LL;
+int head[MAXN],e;
+LL dis[MAXN];
+bool vis[MAXN];
+struct Edge{
+    int v,nxt,w;
+}E[MAXN<<1];
+void init()
+{
+    e=0;
+    memset(head,-1,sizeof head);
+    memset(vis,false,sizeof vis);
+}
+void add(int u,int v,int w)
+{
+    E[e].v = v;
+    E[e].w = w;
+    E[e].nxt = head[u];
+    head[u]  = e++;
+}
+struct QNode{
+    int v,c;
+    QNode(int _v,int _c){
+        v = _v;c=_c;
+    }
+    bool operator < (const QNode &a) const{
+        return c>a.c;
+    }
+};
+LL dijkstra(int n)
+{
+    memset(dis,INF,sizeof dis);
+    priority_queue<QNode>Q;
+    dis[1] = 0;
+    Q.push(QNode(1,0));
+    while(!Q.empty())
+    {
+        QNode tmp = Q.top();Q.pop();
+        int u = tmp.v;
+        if(vis[u]) continue;
+        vis[u] = true;
+        for(int i=head[u];~i;i=E[i].nxt){
+            int v = E[i].v;
+            int w = E[i].w;
+            if(vis[v]) continue;
+            if(dis[u]+w<dis[v]){
+                dis[v] = dis[u]+w;
+                Q.push(QNode(v,dis[v]));
+            }
+        }
+    }
+    return dis[n];
+}
+LL BFS(int n,LL val)
+{
+    set<int>ta,tb;
+    queue<int>Q;Q.push(1);
+    dis[1] = 0,dis[n] = INF;
+    for(int i=2;i<=n;i++) ta.insert(i);
+    while(!Q.empty())
+    {
+        int u = Q.front();Q.pop();
+        for(int i=head[u];~i;i=E[i].nxt){
+            int v = E[i].v;
+            if(!ta.count(v)) continue;
+            ta.erase(v);tb.insert(v);
+        }
+        for(set<int>::iterator it=ta.begin();it!=ta.end();it++){
+            Q.push(*it);
+            dis[*it] = dis[u] + val;
+        }
+        ta.swap(tb);tb.clear();
+    }
+    return dis[n];
+}
+int main()
+{
+    int N,M;
+    LL A,B;
+    int u,v;
+    while(~scanf("%d%d%lld%lld",&N,&M,&A,&B))
+    {
+        init();
+        bool flag = false;
+        for(int i=0;i<M;i++){
+            scanf("%d%d",&u,&v);
+            add(u,v,A);add(v,u,A);
+            if(min(u,v)==1&&max(u,v)==N)flag  =true;
+        }
+        if(!flag) printf("%lld\n",min(dijkstra(N),(LL)B));
+        else printf("%lld\n",min(BFS(N,B),(LL)A));
+    }
+    return 0;
+}