Compilare: user.cpp: In function ‘int main()’: user.cpp:32:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[s].size();i++) ~^~~~~~~~~~~~ user.cpp:16:22: warning: unused variable ‘s’ [-Wunused-variable] int n , m ,x , y,s,i,z; ^ 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("dijkstra.in","r",stdin); ^ user.cpp:15:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dijkstra.out","w",stdout); ^ user.cpp:17:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:20:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&x,&y,&z); ^