Eroare de compilare: user.cpp: In function ‘bool check(int)’: user.cpp:20: error: conversion from ‘__gnu_cxx::__normal_iterator<std::pair<short int, short int>*, std::vector<std::pair<short int, short int>, std::allocator<std::pair<short int, short int> > > >’ to non-scalar type ‘__gnu_cxx::__normal_iterator<std::pair<int, int>*, std::vector<std::pair<int, int>, std::allocator<std::pair<int, int> > > >’ requested user.cpp:20: error: no match for ‘operator!=’ in ‘it != A[ret].std::vector<_Tp, _Alloc>::end [with _Tp = std::pair<short int, short int>, _Alloc = std::allocator<std::pair<short int, short int> >]()’