Compilare: user.cpp: In function ‘void euler(int)’: user.cpp:20:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < G[nd].size(); i++) { ^ user.cpp: In function ‘int main()’: user.cpp:45:21: warning: suggest parentheses around comparison in operand of ‘&’ [-Wparentheses] if (grad[i] & 1 != 0) { ^ user.cpp:57:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < G[i].size(); j++) { ^