skyscraper.cpp: In function 'int main()':
skyscraper.cpp:23:13: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
23 | for (auto& [q, v] : make) {
| ^
skyscraper.cpp:24:8: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
24 | auto [p, i] = q;
| ^
skyscraper.cpp:28:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
28 | for (int n = 0; n < fr.size(); ++n) {
| ~~^~~~~~~~~~~
skyscraper.cpp:42:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
42 | if (n + 1 < fr.size()) G[s].push_back(fr[n + 1]);
| ~~~~~~^~~~~~~~~~~
skyscraper.cpp:44:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
44 | if (n + 2 < fr.size()) G[s].push_back(node - 2 * fr.size() + n + 2);
| ~~~~~~^~~~~~~~~~~
skyscraper.cpp:62:32: warning: 'E' may be used uninitialized in this function [-Wmaybe-uninitialized]
62 | cout << (D[E] > 1E9 ? -1 : D[E]);
| ~~~^