Compilare: main.cpp: In function 'bool check(int)': main.cpp:72:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 72 | for (i = 0; i < v.size(); i++) | ~~^~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:83:9: warning: unused variable 'len' [-Wunused-variable] 83 | int len = 0; | ^~~