Compilare: user.cpp: In function ‘void qs(int, int)’: user.cpp:27:36: warning: operation on ‘l[j]’ may be undefined [-Wsequence-point] l[i]=(l[i]^l[j])^(l[j]=l[i]); ^ user.cpp:28:36: warning: operation on ‘c[j]’ may be undefined [-Wsequence-point] c[i]=(c[i]^c[j])^(c[j]=c[i]); ^ user.cpp: In function ‘void qss(int, int)’: user.cpp:42:41: warning: operation on ‘no[j]’ may be undefined [-Wsequence-point] no[i]=(no[i]^no[j])^(no[j]=no[i]); ^ user.cpp: In function ‘void read()’: user.cpp:13:28: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d",&n,&k); ^ user.cpp:16:31: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d",&l[i],&c[i]); ^