Compilare: main.cpp: In function 'void scan()': main.cpp:20:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 2; j < s.length(); ++j) { ~~^~~~~~~~~~~~ main.cpp: In function 'std::vector<int> reuniune(std::vector<int>, std::vector<int>)': main.cpp:37:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i < a.size() && j < b.size()) { ~~^~~~~~~~~~ main.cpp:37:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i < a.size() && j < b.size()) { ~~^~~~~~~~~~ main.cpp:53:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i < a.size()) { ~~^~~~~~~~~~ main.cpp:58:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (j < b.size()) { ~~^~~~~~~~~~ main.cpp: In function 'std::vector<int> intersectie(std::vector<int>, std::vector<int>)': main.cpp:70:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i < a.size() && j < b.size()) { ~~^~~~~~~~~~ main.cpp:70:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i < a.size() && j < b.size()) { ~~^~~~~~~~~~