Compilare: main.cpp: In function 'int main()': main.cpp:6:91: 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),freopen("fmcm.out","w",stdout),scanf("%d%d%d%d",&n,&m,&s,&t); ^ main.cpp:6:91: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] main.cpp:6:91: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] main.cpp:8:98: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&u,&v,&cp,&cs),c[u][v]=cp,d[u][v]=cs,d[v][u]=-cs,z[u][g[u]++]=v,z[v][g[v]++]=u; ^