Compilare: user.cpp: In function ‘int main()’: user.cpp:28:33: warning: unused variable ‘k’ [-Wunused-variable] int n, m, i, j, x, y, a, b, k, nod, poz, mini; ^ user.cpp: In function ‘void BFS(int)’: user.cpp:76:9: warning: unused variable ‘i’ [-Wunused-variable] int i, j, nod; ^ user.cpp:76:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j, nod; ^ user.cpp: In function ‘int main()’: user.cpp:25:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("marmelada.in","r",stdin); ^ user.cpp:26:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("marmelada.out","w",stdout); ^ user.cpp:31:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&n,&m,&a,&b); ^ user.cpp:33:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^ user.cpp:39:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&cost_drum[ i ].cost); ^