Eroare de compilare: user.cpp: In function ‘double dist(pct, seg)’: user.cpp:27:29: error: call of overloaded ‘abs(double)’ is ambiguous return abs(P.x*a+P.y*b+c)/sqrt(pow(a,2)+pow(b,2)); ^ user.cpp:27:29: note: candidates are: In file included from /usr/include/c++/4.8/cstdlib:72:0, from /usr/include/c++/4.8/ext/string_conversions.h:41, from /usr/include/c++/4.8/bits/basic_string.h:2815, from /usr/include/c++/4.8/string:52, from /usr/include/c++/4.8/bits/locale_classes.h:40, from /usr/include/c++/4.8/bits/ios_base.h:41, from /usr/include/c++/4.8/ios:42, from /usr/include/c++/4.8/ostream:38, from /usr/include/c++/4.8/iostream:39, from user.cpp:1: /usr/include/stdlib.h:771:12: note: int abs(int) extern int abs (int __x) __THROW __attribute__ ((__const__)) __wur; ^ In file included from /usr/include/c++/4.8/ext/string_conversions.h:41:0, from /usr/include/c++/4.8/bits/basic_string.h:2815, from /usr/include/c++/4.8/string:52, from /usr/include/c++/4.8/bits/locale_classes.h:40, from /usr/include/c++/4.8/bits/ios_base.h:41, from /usr/include/c++/4.8/ios:42, from /usr/include/c++/4.8/ostream:38, from /usr/include/c++/4.8/iostream:39, from user.cpp:1: /usr/include/c++/4.8/cstdlib:174:3: note: long long int std::abs(long long int) abs(long long __x) { return __builtin_llabs (__x); } ^ /usr/include/c++/4.8/cstdlib:166:3: note: long int std::abs(long int) abs(long __i) { return __builtin_labs(__i); } ^ user.cpp: In function ‘int inters(seg, seg)’: user.cpp:51:10: warning: statement has no effect [-Wunused-value] k==0; ^ user.cpp: In function ‘int main()’: user.cpp:121:23: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(z) ^ user.cpp: In function ‘int inters(seg, seg)’: user.cpp:93:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘double dist(pct, seg)’: user.cpp:28:1: warning: control reaches end of non-void function [-Wreturn-type] } ^