Eroare de compilare: user.cpp: In function ‘int main()’: user.cpp:41:29: error: call of overloaded ‘abs(double)’ is ambiguous b=(abs(sum-n*(n-1)/2)<0.0001)?b:(false); ^ user.cpp:41:29: 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/istream:38, from /usr/include/c++/4.8/fstream:38, from user.cpp:1: /usr/include/stdlib.h:771:12: note: int abs(int) extern int abs (int __x) __THROW __attribute__ ((__const__)) __wur; ^ user.cpp:11:8: note: double abs(double) double abs(double x) ^ In file included from /usr/include/c++/4.8/random:38:0, from /usr/include/c++/4.8/bits/stl_algo.h:65, from /usr/include/c++/4.8/algorithm:62, from user.cpp:2: /usr/include/c++/4.8/cmath:91:3: note: constexpr long double std::abs(long double) abs(long double __x) ^ /usr/include/c++/4.8/cmath:87:3: note: constexpr float std::abs(float) abs(float __x) ^ /usr/include/c++/4.8/cmath:81:3: note: constexpr double std::abs(double) abs(double __x) ^ 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/istream:38, from /usr/include/c++/4.8/fstream:38, 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); } ^