Compilare: user.cpp: In function ‘void read()’: user.cpp:21:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < a.size(); i++) ^ user.cpp: In function ‘void solve()’: user.cpp:27:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0, idx, min = 0; i < a.size(); i++) ^ user.cpp:30:28: warning: ‘idx’ may be used uninitialized in this function [-Wmaybe-uninitialized] s = a[i] - min, q = idx + 1, w = i; ^