Compilare: user.cpp: In function ‘void readData()’: user.cpp:64:66: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0, needed = n - 1; needed && j < candidates.size(); ++j) ^ user.cpp:52:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d ", &n, &m, &q); ^ user.cpp:56:42: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d ", &a, &b, &cost); ^