HDU4396 More lumber is required

2012 Multi-University Training Contest 10
1007 questions
Two-dimensional shortest path.

[Cpp]
# Include <cstdio>
# Include <cstring>
# Include <algorithm>
Using namespace std;
Const int MAXN = 5005;
Const int MAXM = 200005;
Const int MAXK = 505;
Const int MAXQ = MAXN * MAXK;
Constint INF = 1000000000;
 
Struct Edge
{
Int v, w, next;
} Edge [MAXM];
Int edgeNumber, head [MAXN];
Int n, m;
Int s, t, k;
Int ans;
 
Inline void clearEdge ()
{
EdgeNumber = 0;
Memset (head,-1, sizeof (head ));
}
 
Inline void addEdge (int u, int v, int w)
{
Edge [edgeNumber]. v = v;
Edge [edgeNumber]. w = w;
Edge [edgeNumber]. next = head [u];
Head [u] = edgeNumber ++;
}
 
Int queue [MAXQ] [2];
Bool visit [MAXN] [MAXK];
Int dist [MAXN] [MAXK];
 
Void solve ()
{
Ans =-1;
Int front = 0, rear = 1;
For (int I = 1; I <= n; ++ I)
{
For (int j = 0; j <= k; ++ j)
{
Visit [I] [j] = false;
Dist [I] [j] = INF;
}
}
Queue [0] [0] = s;
Queue [0] [1] = 0;
Visit [s] [0] = true;
Dist [s] [0] = 0;
While (front! = Rear)
{
Int u = queue [front] [0];
Int uk = queue [front] [1];
For (int I = head [u]; I! =-1; I = edge [I]. next)
{
Int v = edge [I]. v;
Int vk = uk + 10;
Int w = edge [I]. w;
If (vk> k)
{
Vk = k;
}
If (dist [v] [vk]> dist [u] [uk] + w)
{
Dist [v] [vk] = dist [u] [uk] + w;
If (v = t & vk = k)
{
Ans = dist [v] [vk];
}
If (! Visit [v] [vk])
{
Visit [v] [vk] = true;
Queue [rear] [0] = v;
Queue [rear] [1] = vk;
If (++ rear> = MAXQ)
{
Rear = 0;
}
}
}
}
Visit [u] [uk] = false;
If (++ front> = MAXQ)
{
Front = 0;
}
}
}
 
Int main ()
{
Int u, v, w;
While (~ Scanf ("% d", & n, & m ))
{
ClearEdge ();
For (int I = 0; I <m; ++ I)
{
Scanf ("% d", & u, & v, & w );
AddEdge (u, v, w );
AddEdge (v, u, w );
}
Scanf ("% d", & s, & t, & k );
Solve ();
Printf ("% d \ n", ans );
}
Return 0;
}