Compilare: user.cpp: In function ‘int main()’: user.cpp:133:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (Ones(left) == left.size()) { ^ user.cpp:135:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (rz < left.size()) { ^ user.cpp:154:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < left.size(); ++j) { ^ user.cpp:166:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < left.size(); ++j) { ^ user.cpp:191:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if ((_num & 1) != B[pos] - '0') { ^ user.cpp:92:54: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("infinitepatternmatching.in", "r", stdin); ^ user.cpp:93:56: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("infinitepatternmatching.out", "w", stdout); ^ user.cpp:94:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("debug.err", "w", stderr); ^