Compilare: main.cpp: In function 'int main()': main.cpp:80:94: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("heavypath.in","r",stdin),freopen("heavypath.out","w",stdout),scanf("%d%d",&N,&M); ^ main.cpp:80:94: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] main.cpp:80:94: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] main.cpp:82:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",v+i); ^ main.cpp:84:64: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&a,&b),G[a].push_back(b),G[b].push_back(a); ^ main.cpp:86:67: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&t,&x,&y),op[i]=make_pair(t,make_pair(x,y)); ^