Compilare: user.cpp: In function ‘void bfs(int)’: user.cpp:22:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(b=0; b<g[a].size(); ++b) ^ user.cpp:18:15: warning: unused variable ‘c’ [-Wunused-variable] int a, b, c; ^ user.cpp: In function ‘void drum(int)’: user.cpp:40:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(f=0; f<l[i].size(); ++f)drum(l[i][f]); ^ user.cpp:39:12: warning: unused variable ‘r’ [-Wunused-variable] int f, r; ^ user.cpp: In function ‘int main()’: user.cpp:61:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0; j<g[i].size(); ++j) ^ user.cpp:46:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("graf.in", "r", stdin); ^ user.cpp:47:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("graf.out", "w", stdout); ^ user.cpp:48:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &n, &m, &x, &y); ^ user.cpp:51:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &j, &k); ^