Compilare: user.cpp: In function ‘int main()’: user.cpp:37:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<vlin.size();i++) ^ user.cpp:39:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<vcol.size();i++) ^ user.cpp:46:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<vlin.size();i++){ ^ user.cpp:48:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0,s=0;j<vcol.size();j++){ ^ user.cpp:16:7: warning: unused variable ‘m’ [-Wunused-variable] int n,m,k,i,j,s,valmax=-2000000000; ^ user.cpp:16:17: warning: unused variable ‘valmax’ [-Wunused-variable] int n,m,k,i,j,s,valmax=-2000000000; ^ user.cpp:14:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dreptunghiuri4.in","r",stdin); ^ user.cpp:15:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dreptunghiuri4.out","w",stdout); ^ user.cpp:18:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&k); ^ user.cpp:20:54: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&v[i].x1,&v[i].y1,&v[i].x2,&v[i].y2); ^