Shallow waters

input/code.cpp: In function 'void bfs(int)':
input/code.cpp:46:17: error: request for member 'first' in 'x', which is of non-class type 'int'
   46 |       int v = x.first, w = x.second;
      |                 ^~~~~
input/code.cpp:48:20: error: 'w' was not declared in this scope
   48 |         d[v] = min(w, d[u]);
      |                    ^
In file included from /usr/include/x86_64-linux-gnu/c++/11/bits/c++allocator.h:33,
                 from /usr/include/c++/11/bits/allocator.h:46,
                 from /usr/include/c++/11/string:41,
                 from /usr/include/c++/11/bits/locale_classes.h:40,
                 from /usr/include/c++/11/bits/ios_base.h:41,
                 from /usr/include/c++/11/ios:42,
                 from /usr/include/c++/11/istream:38,
                 from /usr/include/c++/11/sstream:38,
                 from /usr/include/c++/11/complex:45,
                 from /usr/include/c++/11/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/1...

#include <bits/stdc++.h>

using namespace std;

const int N = 5e2 + 5;

struct dsu {
  int lab[N];

  dsu() {
    memset(lab, -1, sizeof(lab));
  }

  int find(int u) {
    return lab[u] < 0 ? u : lab[u] = find(lab[u]);
  }

  bool merge(int u, int v) {
    if ((u = find(u)) == (v = find(v))) {
      return false;
    }
    if (lab[u] > lab[v]) {
      swap(u, v);
    }
    lab[u] += lab[v];
    lab[v] = u;
    return true;
  }
};

int n, q;
vector<array<int, 3> > e;
vector<int> adj[N];
dsu g;
int d[N];

void bfs(int src) {
  memset(d, -1, sizeof(d));
  queue<int> q;
  q.push(src);
  d[src] = 0x3f3f3f3f;
  while (!q.empty()) {
    int u = q.front();
    q.pop();
    for (auto x : adj[u]) {
      int v = x.first, w = x.second;
      if (d[v] == -1) {
        d[v] = min(w, d[u]);
        q.push(v);
      }
    }
  }
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cin >> n >> q;
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= n; j++) {
      int a;
      cin >> a;
      e.emplace_back(array<int, 3>{-a, i, j});
    }
  }
  sort(e.begin(), e.end());
  for (auto x : e) {
    if (g.merge(x[1], x[2])) {
      adj[x[1]].emplace_back(x[2], -x[0]);
      adj[x[2]].emplace_back(x[1], -x[0]);
    }
  }
  while (q--) {
    int x, y;
    cin >> x >> y;
    bfs(x);
    cout << d[y] << '\n';
  }
  return 0;
}