Compilare: main.cpp: In function 'int main()': main.cpp:47:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 47 | for (i = 0; i < w.size(); i++) { | ~~^~~~~~~~~~ main.cpp:63:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 63 | for (i = 0; i < a[x].size(); i++) | ~~^~~~~~~~~~~~~