foo.cc: In function 'void dfs(std::vector<std::vector<int> >&, int)':
foo.cc:12:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 |  if (pos == spaces.size()) {
      |      ~~~~^~~~~~~~~~~~~~~~
foo.cc: In function 'int main()':
foo.cc:45:2: error: 'memset' was not declared in this scope
   45 |  memset(line, false, sizeof(line));
      |  ^~~~~~
foo.cc:3:1: note: 'memset' is defined in header '<cstring>'; did you forget to '#include <cstring>'?
    2 | #include<vector>
  +++ |+#include <cstring>
    3 | using namespace std;

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