hdu 1142 A Walk Through the Forest Dijkstra+记忆搜索

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#include<iostream>using namespace std;const int MAX=2147483647;int n,m;int t1,t2,len;int map[1005][1005];int ans[1005];int isvisit[1005];int answer;void Dijkstra();int DFS(int k);int main(){while(cin>>n,n){answer=0;memset(isvisit,-1,sizeof(isvisit));for(int i=1;i<=n;i++){ans[i]=MAX;for(int j=1;j<=n;j++){map[i][j]=MAX;}}cin>>m;for(i=0;i<m;i++){cin>>t1>>t2>>len;if(map[t1][t2]>len)map[t1][t2]=map[t2][t1]=len;}Dijkstra();//for(i=1;i<=n;i++)//{//cout<<ans[i]<<endl;//}cout<<DFS(1)<<endl;}return 0;}void Dijkstra(){int visit[1005]={0};int k;ans[2]=0;for(int i=1;i<=n;i++){k=-1;for(int j=1;j<=n;j++){if(!visit[j] && ( k==-1 || ans[j]<ans[k]) )k=j;}visit[k]=1;for(j=1;j<=n;j++){if(!visit[j] && ans[j]>ans[k]+map[k][j] && map[k][j]!=MAX)ans[j]=ans[k]+map[k][j];}}}int DFS(int k){int temp=0;if(isvisit[k]!=-1)return isvisit[k];if(k==2){return 1;}for(int i=1;i<=n;i++){if(map[k][i]!=MAX && ans[k]>ans[i])temp+=DFS(i);}isvisit[k]=temp;return temp;}