SPFA算法模板

const int INF=0x3f3f3f3f;const int maxm=511111;const int maxn=111111;struct EdgeNode{    int to;    int w;    int next;};EdgeNode edges[maxm];int N,M;int head[maxn],edge;bool vis[maxn];queue <int> que;int dis[maxn];void addedge(int u,int v,int c){    edges[edge].w=c,edges[edge].to=v,edges[edge].next=head[u],head[u]=edge++;}void init(){    memset(head,-1,sizeof(head));    edge=0;}void spfa(int s,int n)//单源最短路(s为起点，n为节点总数){    int u;    for (int i=0; i<=n; i++)        dis[i]=INF;    memset(vis,0,sizeof(vis));    while (!que.empty()) que.pop();    que.push(s);    vis[s]=true;    dis[s]=0;    while (!que.empty())    {        u=que.front();        que.pop();        vis[u]=false;        for (int i=head[u]; i!=-1; i=edges[i].next)        {            int v=edges[i].to;            int w=edges[i].w;            if (dis[v]>dis[u]+w)            {                dis[v]=dis[u]+w;                if (!vis[v])                {                    vis[v]=true;                    que.push(v);                }            }        }    }}