Eroare de compilare: user.cpp: In function ‘double sortare(double, double, double, double)’: user.cpp:16:16: warning: left operand of comma operator has no effect [-Wunused-value] return (x1,x2,y1,y2)<0; ^ user.cpp:16:19: warning: right operand of comma operator has no effect [-Wunused-value] return (x1,x2,y1,y2)<0; ^ user.cpp:16:22: warning: right operand of comma operator has no effect [-Wunused-value] return (x1,x2,y1,y2)<0; ^ user.cpp: In function ‘int main()’: user.cpp:34:45: warning: unused variable ‘j’ [-Wunused-variable] int i,maxx=1000000003,maxy=1000000003,x,j,l=3; ^ In file included from /usr/include/c++/4.8/algorithm:62:0, from user.cpp:3: /usr/include/c++/4.8/bits/stl_algo.h: In instantiation of ‘void std::__insertion_sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = std::pair<double, double>*; _Compare = double (*)(double, double, double, double)]’: /usr/include/c++/4.8/bits/stl_algo.h:2250:70: required from ‘void std::__final_insertion_sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = std::pair<double, double>*; _Compare = double (*)(double, double, double, double)]’ /usr/include/c++/4.8/bits/stl_algo.h:5514:55: required from ‘void std::sort(_RAIter, _RAIter, _Compare) [with _RAIter = std::pair<double, double>*; _Compare = double (*)(double, double, double, double)]’ user.cpp:54:33: required from here /usr/include/c++/4.8/bits/stl_algo.h:2183:29: error: cannot convert ‘std::pair<double, double>’ to ‘double’ in argument passing if (__comp(*__i, *__first)) ^ /usr/include/c++/4.8/bits/stl_algo.h: In instantiation of ‘void std::__heap_select(_RandomAccessIterator, _RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = std::pair<double, double>*; _Compare = double (*)(double, double, double, double)]’: /usr/include/c++/4.8/bits/stl_algo.h:5363:59: required from ‘void std::partial_sort(_RAIter, _RAIter, _RAIter, _Compare) [with _RAIter = std::pair<double, double>*; _Compare = double (*)(double, double, double, double)]’ /usr/include/c++/4.8/bits/stl_algo.h:2355:68: required from ‘void std::__introsort_loop(_RandomAccessIterator, _RandomAccessIterator, _Size, _Compare) [with _RandomAccessIterator = std::pair<double, double>*; _Size = int; _Compare = double (*)(double, double, double, double)]’ /usr/include/c++/4.8/bits/stl_algo.h:5513:44: required from ‘void std::sort(_RAIter, _RAIter, _Compare) [with _RAIter = std::pair<double, double>*; _Compare = double (*)(double, double, double, double)]’ user.cpp:54:33: required from here /usr/include/c++/4.8/bits/stl_algo.h:1972:27: error: cannot convert ‘std::pair<double, double>’ to ‘double’ in argument passing if (__comp(*__i, *__first)) ^ /usr/include/c++/4.8/bits/stl_algo.h: In instantiation of ‘void std::__move_median_first(_Iterator, _Iterator, _Iterator, _Compare) [with _Iterator = std::pair<double, double>*; _Compare = double (*)(double, double, double, double)]’: /usr/include/c++/4.8/bits/stl_algo.h:2318:68: required from ‘_RandomAccessIterator std::__unguarded_partition_pivot(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = std::pair<double, double>*; _Compare = double (*)(double, double, double, double)]’ /usr/include/c++/4.8/bits/stl_algo.h:2360:62: required from ‘void std::__introsort_loop(_RandomAccessIterator, _RandomAccessIterator, _Size, _Compare) [with _RandomAccessIterator = std::pair<double, double>*; _Size = int; _Compare = double (*)(double, double, double, double)]’ /usr/include/c++/4.8/bits/stl_algo.h:5513:44: required from ‘void std::sort(_RAIter, _RAIter, _Compare) [with _RAIter = std::pair<double, double>*; _Compare = double (*)(double, double, double, double)]’ user.cpp:54:33: required from here /usr/include/c++/4.8/bits/stl_algo.h:110:28: error: cannot convert ‘std::pair<double, double>’ to ‘double’ in argument passing if (__comp(*__a, *__b)) ^ /usr/include/c++/4.8/bits/stl_algo.h:112:25: error: cannot convert ‘std::pair<double, double>’ to ‘double’ in argument passing if (__comp(*__b, *__c)) ^ /usr/include/c++/4.8/bits/stl_algo.h:114:30: error: cannot convert ‘std::pair<double, double>’ to ‘double’ in argument passing else if (__comp(*__a, *__c)) ^ /usr/include/c++/4.8/bits/stl_algo.h:117:33: error: cannot convert ‘std::pair<double, double>’ to ‘double’ in argument passing else if (__comp(*__a, *__c)) ^ /usr/include/c++/4.8/bits/stl_algo.h:119:33: error: cannot convert ‘std::pair<double, double>’ to ‘double’ in argument passing else if (__comp(*__b, *__c))