foo.cc:1:30: warning: '-std=c++17' is not an option that controls warnings [-Wpragmas]
    1 | #pragma GCC diagnostic error "-std=c++17"
      |                              ^~~~~~~~~~~~
foo.cc: In function 'void dfs(int, int)':
foo.cc:17:12: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   17 |  for (auto [nextId, edgId] : edges[nodeId]) {
      |            ^
foo.cc: In function 'int main()':
foo.cc:28:26: error: missing template arguments before '(' token
   28 |   edges[u].push_back(pair(v, i));
      |                          ^
foo.cc:29:26: error: missing template arguments before '(' token
   29 |   edges[v].push_back(pair(u, i));
      |                          ^
foo.cc:48:23: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   48 |    if (travSeq.size() != n) {
      |        ~~~~~~~~~~~~~~~^~~~

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