Compilare: main.cpp: In function 'void sortare_topologica()': main.cpp:29:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<g[a].size(); i++) ~^~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:42:15: warning: unused variable 'cc' [-Wunused-variable] int u, v, cc, i; ^~ main.cpp:40:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("sortaret.in", "r", stdin); ^ main.cpp:41:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("sortaret.out", "w", stdout); ^ main.cpp:43:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ main.cpp:46:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &u, &v); ^