Compilare: user.cpp: In function ‘bool explore(std::vector<int>, int)’: user.cpp:13:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v.size(); i ++) { ~~^~~~~~~~~~ user.cpp:14:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = i + 1; j < v.size(); j ++) { ~~^~~~~~~~~~ user.cpp:22:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int ii = j + 1; ii < v.size(); ii ++) ~~~^~~~~~~~~~