Compilare: user.cpp: In function ‘void dijkstra(const int&)’: user.cpp:22:11: warning: variable ‘cost’ set but not used [-Wunused-but-set-variable] int x,cost,y,z; ^ user.cpp: In function ‘int main()’: user.cpp:68:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dbz.in","r",stdin); ^ user.cpp:69:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dbz.out","w",stdout); ^ user.cpp:70:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:72:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&x,&y,&z); ^