Compilare: main.cpp: In function 'bool b_ford()': main.cpp:46:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<G[nod].size();j++) ~^~~~~~~~~~~~~~ main.cpp: In function 'void read()': main.cpp:15:33: 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); ^ main.cpp:17:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&n,&m,&s,&d); ^ main.cpp:20:41: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&x,&y,&z,&cost); ^ main.cpp: In function 'int main()': main.cpp:136:35: 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); ^