poj 3169——Layout

来源：互联网发布：如何理解 js的闭包编辑：程序博客网时间：2024/06/05 20:43

查分约束

#include<iostream>#include<cstdio>#include<cstring>#include<queue>using namespace std;#define INF 1000001int head[30000],v[30000],w[30000],next[30000];int dis[2000],vis[2000],output[2000];int cnt,n,l,d;void add(int a,int b,int c){v[cnt]=b;w[cnt]=c;next[cnt]=head[a];head[a]=cnt++;}int spfa(){memset(vis,0,sizeof(vis));memset(output,0,sizeof(output));for(int i=1;i<=n;i++)dis[i]=INF;queue<int> q;q.push(1);vis[1]=1;dis[1]=0;while(!q.empty()){int u=q.front();q.pop();vis[u]=0;output[u]++;if(output[u]>n)return -1;for(int i=head[u];i!=-1;i=next[i])if(dis[v[i]]>dis[u]+w[i]){dis[v[i]]=dis[u]+w[i];if(!vis[v[i]]){vis[v[i]]=1;q.push(v[i]);}}}return dis[n];}int main(){while(~scanf("%d%d%d",&n,&l,&d)){cnt=0;memset(head,-1,sizeof(head));for(int i=0;i<l;i++){int x,y,z;scanf("%d%d%d",&x,&y,&z);add(x,y,z);}for(int i=0;i<d;i++){int x,y,z;scanf("%d%d%d",&x,&y,&z);add(y,x,-z);}int temp=spfa();if(temp==-1)printf("-1\n");else{if(temp==INF)printf("-2\n");elseprintf("%d\n",temp);}}return 0;}