最短路模板

for(register int k=1;k<=n;k++)//Floyd
    for(register int i=1;i<=n;i++)
        for(register int j=1;j<=n;j++) dis[i][j] = min(dis[i][k]+dis[k][j] ,dis[i][j]); 

//spfa
inline void add(int from,int to,int dis){
    edge[++cnt].nxt=head[from];
    edge[cnt].to=to;
    edge[cnt].dis=dis;
    head[from]=cnt;
    return ;
}
inline void Spfa(){
    queue<int>q;
    for(register int i=1;i<=n;i++) dis[i]=0x7fffffff,vis[i]=0;
    q.push(s);
    dis[s]=0;
    vis[s]=1;
    while(!q.empty()){
        int u=q.front();
        q.pop();
        vis[u]=0;
        for(register int i=head[u];i;i=edge[i].nxt){
            int v=edge[i].to;
            if(dis[v]>dis[u]+edge[i].dis){
                dis[v]=dis[u]+edge[i].dis;
                if(!vis[v]) vis[v]=1,q.push(v);
            }
        }
    }
}

//dijkstra
inline void add_edge( int u, int v, int d ) {
    cnt++;
    e[cnt].dis = d;
    e[cnt].to = v;
    e[cnt].next = head[u];
    head[u] = cnt;
}
struct node {
    int dis;
    int pos;
    bool operator <( const node &x )const {
        return x.dis < dis;
    }
};
std::priority_queue<node> q;
inline void dijkstra() {
    dis[s] = 0;
    q.push( ( node ) {
        0, s
    } );
    while( !q.empty() ) {
        node tmp = q.top();
        q.pop();
        int x = tmp.pos, d = tmp.dis;
        if( vis[x] )
            continue;
        vis[x] = 1;
        for( int i = head[x]; i; i = e[i].next ) {
            int y = e[i].to;
            if( dis[y] > dis[x] + e[i].dis ) {
                dis[y] = dis[x] + e[i].dis;
                if( !vis[y] ) {
                    q.push( ( node ) {
                        dis[y], y
                    } );
                }
            }
        }
    }
}

最短路的题目