Compilare: user.cpp: In function ‘void Subtract1(std::vector<int>&, std::vector<int>&)’: user.cpp:95:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i != a.size() && a[i] == bit) { ^ user.cpp:99:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (j != b.size() && b[j] == bit) { ^ user.cpp: In function ‘char Advance()’: user.cpp:25:38: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer, 1, SIZE, stdin); ^ user.cpp: In function ‘int main()’: user.cpp:117:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("greutati.in", "r", stdin); ^ user.cpp:118:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("greutati.out", "w", stdout); ^ user.cpp:120:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &p); ^ user.cpp:122:49: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &v[i].first, &v[i].second); ^