Compilare: main.cpp: In function 'int main()': main.cpp:59:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<euler.size(); ++i) { ~^~~~~~~~~~~~~ main.cpp:75:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=0; j<pos[i].size(); ++j) { ~^~~~~~~~~~~~~~ main.cpp:76:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (j+1 < pos[i].size()) { ~~~~^~~~~~~~~~~~~~~