#include <bits/stdc++.h>
using namespace std;
int hsh(pair<int,int> pr)
{
return pr.first * 31000 + pr.second;
}
pair<int,int> dehsh(int x)
{
return {x / 31000, x % 31000};
}
int n,m;
int b[30005],p[30005];
unordered_map<int, bool> viz,luat;
unordered_map<int, int> d;
vector<int> what[30005];
int str,fin;
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
cin >> n >> m;
for (int i = 1; i <= m; i++)
cin >> b[i] >> p[i],what[b[i]].push_back(p[i]);
str = b[1],fin = b[2];
deque<pair<int,int>> q;
q.push_back({str,0});
viz[hsh({str,0})] = true;
int lul = 2e7;
while (!q.empty())
{
pair<int,int> nod = q.front();
int dehnod = hsh(nod);
q.pop_front();
if (luat[dehnod])
continue;
cate++;
if (cate > lul)
assert(false);
luat[dehnod] = true;
int dist = d[dehnod];
if (nod.second != 0)
{
pair<int,int> vec;
vec = {nod.first,0};
int dehvec = hsh(vec);
if (!viz[dehvec] or d[dehvec] > dist)
{
viz[dehvec] = true;
q.push_front(vec);
d[dehvec] = dist;
}
vec = {nod.first + nod.second,nod.second};
dehvec = hsh(vec);
if (!viz[dehvec] and vec.first >= 0 and vec.first < n)
{
viz[dehvec] = true;
q.push_back(vec);
d[dehvec] = dist + 1;
}
vec = {nod.first - nod.second,nod.second};
dehvec = hsh(vec);
if (!viz[dehvec] and vec.first >= 0 and vec.first < n)
{
viz[dehvec] = true;
q.push_back(vec);
d[dehvec] = dist + 1;
}
}
else
{
for (auto it : what[nod.first])
{
pair<int,int> vec = {nod.first,it};
int dehvec = hsh(vec);
if (!viz[dehvec] or d[dehvec] > dist)
{
viz[dehvec] = true;
q.push_front(vec);
d[dehvec] = dist;
}
}
}
}
if (!viz[hsh({fin,0})])
cout << -1;
else
cout << d[hsh({fin,0})];
return 0;
}
Compilation message
skyscraper.cpp: In function 'int main()':
skyscraper.cpp:42:9: error: 'cate' was not declared in this scope
42 | cate++;
| ^~~~
