Compilare: user.cpp: In function ‘int b2to10(std::vector<char, std::allocator<char> >, size_t)’: user.cpp:19: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:41: warning: NULL used in arithmetic user.cpp:41: warning: suggest parentheses around comparison in operand of ‘!=’ user.cpp:28: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result