Compilare: user.cpp: In function ‘int main()’: user.cpp:66:26: warning: unused variable ‘cost’ [-Wunused-variable] int x,y,t,watt,i,K,M,cost,sol=INF,sol2,W,st,dr,mij; ^ user.cpp:66:44: warning: unused variable ‘W’ [-Wunused-variable] int x,y,t,watt,i,K,M,cost,sol=INF,sol2,W,st,dr,mij; ^ user.cpp:67:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("lanterna.in","r",stdin); ^ user.cpp:68:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("lanterna.out","w",stdout); ^ user.cpp:69:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &N,&K); ^ user.cpp:71:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &stare[i]); ^ user.cpp:72:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &M); ^ user.cpp:75:42: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &x,&y,&t,&watt); ^