Eroare de compilare: user.cpp:15:11: error: ‘double y1’ redeclared as different kind of symbol double x1,y1,x2,y2,x3,y3,x4,y4,a,b,mx,my; ^ In file included from /usr/include/features.h:346:0, from /usr/local/include/c++/4.8.0/i686-pc-linux-gnu/bits/os_defines.h:39, from /usr/local/include/c++/4.8.0/i686-pc-linux-gnu/bits/c++config.h:420, from /usr/local/include/c++/4.8.0/utility:68, from /usr/local/include/c++/4.8.0/algorithm:60, from user.cpp:1: /usr/include/bits/mathcalls.h:242:1: error: previous declaration of ‘double y1(double)’ __MATHCALL (y1,, (_Mdouble_)); ^ user.cpp: In function ‘int main()’: user.cpp:25:25: error: assignment of function ‘double y1(double)’ x1=P[i].x,y1=P[i].y,x2=P[j].x,y2=P[j].y; ^ user.cpp:25:25: error: cannot convert ‘double’ to ‘double(double)throw ()’ in assignment user.cpp:26:35: error: invalid operands of types ‘double(double)throw ()’ and ‘double’ to binary ‘operator+’ mx=(x1+x2)*0.5;my=(y1+y2)*0.5; ^ user.cpp:27:18: error: invalid operands of types ‘double(double)throw ()’ and ‘double’ to binary ‘operator-’ a=y1-y2;b=x2-x1; ^