Compilare: user.cpp: In function ‘int main()’: user.cpp:39:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < g[st[r]].size(); i++) ^ user.cpp:50:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < g[nb].size(); i++) ^ user.cpp:77:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < g[nb].size(); i++) ^ user.cpp:13:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("joc4.in", "r", stdin); ^ user.cpp:14:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("joc4.out", "w", stdout); ^ user.cpp:16:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &n, &m, &na, &nb); ^ user.cpp:19:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &a, &b); ^