Compilare: main.cpp: In function 'int dfs(int, int, const std::vector<std::vector<int> >&, std::vector<std::vector<bool> >&, std::pair<int, int>&)': main.cpp:49:49: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 49 | if (lnext < 0 || cnext < 0 || lnext >= a.size() || cnext >= a.size()) | ~~~~~~^~~~~~~~~~~ main.cpp:49:70: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 49 | if (lnext < 0 || cnext < 0 || lnext >= a.size() || cnext >= a.size()) | ~~~~~~^~~~~~~~~~~