Compilare: user.cpp: In function ‘int main()’: user.cpp:21:13: warning: unused variable ‘j’ [-Wunused-variable] int n,i,j,x,y,difmax,lmax=-1,num,st,dr,start,f1,f2,st1,st2,dr1,dr2,rmax,stmax,drmax; ^ user.cpp:21:34: warning: unused variable ‘num’ [-Wunused-variable] int n,i,j,x,y,difmax,lmax=-1,num,st,dr,start,f1,f2,st1,st2,dr1,dr2,rmax,stmax,drmax; ^ user.cpp:21:44: warning: unused variable ‘start’ [-Wunused-variable] int n,i,j,x,y,difmax,lmax=-1,num,st,dr,start,f1,f2,st1,st2,dr1,dr2,rmax,stmax,drmax; ^ user.cpp:21:50: warning: variable ‘f1’ set but not used [-Wunused-but-set-variable] int n,i,j,x,y,difmax,lmax=-1,num,st,dr,start,f1,f2,st1,st2,dr1,dr2,rmax,stmax,drmax; ^ user.cpp:21:53: warning: variable ‘f2’ set but not used [-Wunused-but-set-variable] int n,i,j,x,y,difmax,lmax=-1,num,st,dr,start,f1,f2,st1,st2,dr1,dr2,rmax,stmax,drmax; ^ user.cpp:21:64: warning: unused variable ‘dr1’ [-Wunused-variable] int n,i,j,x,y,difmax,lmax=-1,num,st,dr,start,f1,f2,st1,st2,dr1,dr2,rmax,stmax,drmax; ^ user.cpp:21:68: warning: unused variable ‘dr2’ [-Wunused-variable] int n,i,j,x,y,difmax,lmax=-1,num,st,dr,start,f1,f2,st1,st2,dr1,dr2,rmax,stmax,drmax; ^ user.cpp:21:72: warning: unused variable ‘rmax’ [-Wunused-variable] int n,i,j,x,y,difmax,lmax=-1,num,st,dr,start,f1,f2,st1,st2,dr1,dr2,rmax,stmax,drmax; ^ user.cpp:19:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sir.in","r",stdin); ^ user.cpp:20:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sir.out","w",stdout); ^ user.cpp:23:39: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&n,&x,&y,&difmax); ^ user.cpp:26:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&v[i]); ^