【模板】最短路

int V, E;
int d[MAX_V][MAX_V];

void Floyd()
{
for(int k = 1; k <= V; k+ +)
for(int i = 1; i <= V; i ++)
for(int j = 1; j <= V; j ++)
d[i][j] = min(d[i][j],d[i][k] + d[k][j]);
}

void dijkstra(int s)
{
d[s] = 0;
while(true)
{
int v = -1;
for(int i = 1; i <= V; i ++)
if(!done[i] && (v == -1 || d[i] < d[v]))
v = i;
if(v == -1) break;
done[v] = 1;
for(int i = first[v]; i != -1; i = next[i])
{
int u = es[i].to;
d[u] = min(d[u], d[v] + es[i].cost);
}
}
}

void spfa(int s)
{
d[s] = 0;
q.push(s);
used[s] = 1;
while(!q.empty())
{
int u = q.front();
q.pop();
used[u] = 0;
for(int i = first[u]; i != -1; i = next[i])
{
int v = es[i].to;
if(d[v] > d[u] + es[i].cost )
{
d[v] = d[u] + es[i].cost;
if(!used[v])
{
q.push(v);
used[v] = 1;
}
}
}
}

}