Compilare: main.cpp: In function 'int main()': main.cpp:33:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0;i < a.size();i++){ ~~^~~~~~~~~~ main.cpp:46:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1;i < a.size();i++){ ~~^~~~~~~~~~