Compilare: user.cpp: In function ‘bool verify_Euler_Fleury()’: user.cpp:67:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0;i < G_Fleury[x].size();i++){ ^ user.cpp: In function ‘void eulerian_ciruit_Fleury()’: user.cpp:110:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < G_Fleury[x].size() && edge_type[G_Fleury[x][i].first]!=0)i++; ^ user.cpp:111:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i < G_Fleury[x].size()){ ^ user.cpp:120:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < G_Fleury[x].size() && edge_type[G_Fleury[x][i].first]!=1)i++; ^ user.cpp:121:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i < G_Fleury[x].size()){ ^ user.cpp: In function ‘void read_Fleury()’: user.cpp:30:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ciclueuler.in", "r", stdin); ^ user.cpp:31:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ciclueuler.out", "w", stdout); ^ user.cpp:32:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d ", &N, &M); ^ user.cpp:40:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d ", &x, &y); ^