/* Slow solution to the task Treasure hunt
* Author: Jakub Radoszewski
* Date: 9.06.2011
* Time complexity: O(#nodes * #dig).
* Description: DFS algorithm.
*/
#include <utility>
#include <vector>
#include <algorithm>
using namespace std;
#define INFTY 100000000
/* This node will be created if a path call appears */
int curr;
vector<vector<int> > edges;
inline void add_edge(int a, int b)
{
edges[a].push_back(b);
edges[b].push_back(a);
}
/*****************************************************************************/
void init()
{
edges.push_back(vector<int>()); /* node 0 */
edges.push_back(vector<int>()); /* node 1 */
curr = 2;
}
/*****************************************************************************/
void path(int a, int s)
{
int pop = a;
for (int i = 0; i < s; i++)
{
edges.push_back(vector<int>()); /* node curr */
add_edge(curr, pop);
pop = curr;
curr++;
}
}
/*****************************************************************************/
int dig(int a, int b)
{
vector<int> d, parent;
d.resize(curr, INFTY);
parent.resize(curr, -1);
vector<int> queue;
d[a] = 0;
queue.push_back(a);
for (int i = 0; i < (int)queue.size(); i++)
{
int v = queue[i];
for (int j = 0; j < (int)edges[v].size(); j++)
{
int w = edges[v][j];
if (d[w] == INFTY)
{
d[w] = d[v] + 1;
parent[w] = v;
queue.push_back(w);
if (w == b)
{
/* recovering the path */
int len = (d[w] + 1) / 2;
while (len--)
w = parent[w];
return w;
}
}
}
}
return -1;
}
Compilation message
tre.c:9:10: fatal error: utility: No such file or directory
#include <utility>
^~~~~~~~~
compilation terminated.
tregrader.c:9:10: fatal error: cassert: No such file or directory
#include <cassert>
^~~~~~~~~
compilation terminated.
