Compilare: user.cpp: In function ‘void bellmanford()’: user.cpp:44:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<G[node].size(); ++i) ^ user.cpp: In function ‘bool dijkstra()’: user.cpp:83:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<G[node.idx].size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:125:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("fmcm.in", "r", stdin); ^ user.cpp:126:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("fmcm.out", "w", stdout); ^ user.cpp:130:46: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &n, &m, &source, &sink); ^ user.cpp:134:42: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &x, &y, &c, &p); ^