func_code_string: #include <bits/stdc++.h>   using namespace std;   const int OO = (int)1e6;   set<pair<int, int> > nods;   map<pair<int, int>, bool> vis;   pair<int, int> fr, sc;   int n, r, a, p, ans, sz;   bool ok = true;   int rx[] = {1, 1, 1, 0, 0, -1, -1, -1};   int ry[] = {1, 0, -1, 1, -1, 1, 0, -1};   bool val(pair<int, int> per) { return nods.find(per) != nods.end(); }   void fun(pair<int, int> pos) {     pair<int, int> cur;     queue<pair<int, int> > q;     ans = 0;     q.push(pos);     vis[pos] = true;     sz = 1;     ok = true;     for (; !q.empty() && ok; sz = q.size(), ans++) {       while (ok && sz--) {         pos = q.front();         q.pop();         for (int i = 0; ok && i < 8; i++) {           cur.first = (pos.first) + rx[i];           cur.second = (pos.second) + ry[i];           if (val(cur) && !vis[cur]) {             q.push(cur);             vis[cur] = true;             if (cur == sc) ok = false;           }         }       }     }   }   int main() {     ios::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     cin >> fr.first >> fr.second >> sc.first >> sc.second >> n;     for (int i = 0; i < n; i++) {       cin >> r >> a >> p;       for (int j = a; j <= p; j++) {         nods.insert({r, j});         vis[{r, j}] = false;       }     }     fun(fr);     if (!ok)       cout << ans << endl;     else       cout << -1 << endl;     return 0;   }   