Compilare: user.cpp: In function ‘int main()’: user.cpp:45:79: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(v[vec[vv[i].x][vv[i].y+1].x][vec[vv[i].x][vv[i].y+1].y].size()>maxx) ^ user.cpp:67:83: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(v[vec[vv[i].x][vv[i].y-1].x][vec[vv[i].x][vv[i].y-1].y].size()>maxx) ^ user.cpp:89:87: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(v[vec[vv[i].x+1][vv[i].y].x][vec[vv[i].x+1][vv[i].y].y].size()>maxx) ^ user.cpp:110:87: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(v[vec[vv[i].x-1][vv[i].y].x][vec[vv[i].x-1][vv[i].y].y].size()>maxx) ^ user.cpp:12:9: warning: unused variable ‘j’ [-Wunused-variable] int n,i,j,x,k,a,b,c,d,maxx=1; ^ user.cpp:12:11: warning: unused variable ‘x’ [-Wunused-variable] int n,i,j,x,k,a,b,c,d,maxx=1; ^ user.cpp:12:13: warning: unused variable ‘k’ [-Wunused-variable] int n,i,j,x,k,a,b,c,d,maxx=1; ^ user.cpp:10:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] {freopen ("bile.in","r",stdin); ^ user.cpp:11:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("bile.out","w",stdout); ^ user.cpp:13:15: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:15:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&vv[i].x,&vv[i].y); ^