Compilare: main.cpp: In function 'int main()': main.cpp:89:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 89 | for (int k = 0; k < l_child[i].size(); ++k) { | ~~^~~~~~~~~~~~~~~~~~~ main.cpp:94:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 94 | for (int k = 0; k < r_child[i].size(); ++k) { | ~~^~~~~~~~~~~~~~~~~~~ main.cpp:21:9: warning: unused variable 'v' [-Wunused-variable] 21 | int v; | ^