Compilare: user.cpp: In function ‘void euler(int)’: user.cpp:29:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < G[x].size(); i++) { ^ user.cpp: In function ‘void euler2(int)’: user.cpp:47:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < G[x].size(); i++) { ^ user.cpp: In function ‘int main()’: user.cpp:85:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < stiva.size(); i++) { ^ user.cpp:86:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < G[i].size(); j++) { ^ user.cpp:97:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < stiva2.size(); i++) { ^ user.cpp:103:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < stiva.size(); i++) { ^ user.cpp:102:13: warning: unused variable ‘k’ [-Wunused-variable] int k = 0; ^ user.cpp:114:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < stiva.size(); i++) { ^