Compilare: main.cpp: In function 'int main()': main.cpp:23:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<a[rest].size(); i++){ ~^~~~~~~~~~~~~~~ main.cpp:34:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<a[rest].size(); i++){ ~^~~~~~~~~~~~~~~ main.cpp:45:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<a[rest].size(); i++){ ~^~~~~~~~~~~~~~~