Compilare: user.cpp: In function ‘void solve(std::vector<int>&, std::vector<int>)’: user.cpp:30:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (b.size() == n) ^ user.cpp:64:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] index<b.size()&& ^ user.cpp: In function ‘int main()’: user.cpp:86:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sume.in", "r", stdin); ^ user.cpp:87:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sume.out", "w", stdout); ^ user.cpp:89:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &p); ^ user.cpp:94:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^