Compilare: user.cpp: In function ‘void Bellman_Ford(int, int)’: user.cpp:34:18: warning: variable ‘a’ set but not used [-Wunused-but-set-variable] int a,b; ^ user.cpp:34:20: warning: variable ‘b’ set but not used [-Wunused-but-set-variable] int a,b; ^ user.cpp: In function ‘int main()’: user.cpp:53:27: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d %d ",&n,&m); ^ user.cpp:57:41: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d %d %d ",&x,&y,&cost); ^