Compilare: main.cpp: In function 'int main()': main.cpp:36:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < a.size(); i ++) ~~^~~~~~~~~~ main.cpp:38:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < b.size(); i ++) ~~^~~~~~~~~~ main.cpp:49:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i < a.size(); i ++) { ~~^~~~~~~~~~ main.cpp:55:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i < a.size(); i ++) { ~~^~~~~~~~~~