Poj 3031 Big Christmas Tree (Water spfa)

 

Question:

Because of a technical difficulty, price of an edge will be (sum of weights of all descendant nodes) × (unit price of the edge ).This sentence has never been understood. We thought it was the minimal spanning tree later.

 

To give an undirected graph, calculate the sum of the weights of each node in the shortest path (dis [I]) * of each node.

Note: The edge weight value must be _ int64; undirected graph;

 

 

#include 
 
  #include 
  
   #include #include 
   
    #include
    #include 
     
      #include 
      
       #include 
       
        #include 
        
         #include 
         
          #define LL long long#define _LL __int64using namespace std;const _LL INF = 1e18;const int maxn = 50010;const int maxm = 50010;struct node{int v;_LL w;int next;}edge[2*maxm];int cnt,head[maxn];_LL W[maxn];int n,m;_LL ans,dis[maxn];void init(){cnt = 0;memset(head,-1,sizeof(head));}void add(int u, int v, _LL w){edge[cnt] = (struct node){v,w,head[u]};head[u] = cnt++;}void solve(){int inque[maxn];queue 
          
            que;while(!que.empty()) que.pop();memset(inque,0,sizeof(inque));for(int i = 1; i <= n; i++)dis[i] = INF;dis[1] = 0;inque[1] = 1;que.push(1);while(!que.empty()){int u = que.front();que.pop();inque[u] = 0;for(int i = head[u]; i != -1; i = edge[i].next){int v = edge[i].v;_LL w = edge[i].w;if(dis[v] > dis[u] + w){dis[v] = dis[u] + w;if(!inque[v]){inque[v] = 1;que.push(v);}}}}}int main(){int test;int u,v;_LL w;scanf(%d,&test);while(test--){init();scanf(%d %d,&n,&m);for(int i = 1; i <= n; i++)scanf(%I64d,&W[i]);for(int i = 1; i <= m; i++){scanf(%d %d %I64d,&u,&v,&w);add(u,v,w);add(v,u,w);}solve();ans = 0;bool flag = true;for(int i = 2; i <= n; i++){if(dis[i] == INF){flag = false;break;}ans += dis[i] * W[i];}if(flag == false)printf(No Answer);else printf(%I64d,ans);}return 0;}