Compilare: user.cpp: In function ‘int bS(int, int)’: user.cpp:22:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i + step < Q [x].size () && Q [x][i + step] <= j) ^ user.cpp: In function ‘int main()’: user.cpp:57:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (k < Q [i].size () && Q [i][k] == 0) { ^ user.cpp:65:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (k < Q [i].size () && Q [i][k] == j) { ^ user.cpp:30:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("qxy.in", "r", stdin); ^ user.cpp:31:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("qxy.out", "w", stdout); // !! ^ user.cpp:33:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &n); ^ user.cpp:35:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &v [i]); ^ user.cpp:37:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &q); ^ user.cpp:39:43: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d%d%d", &a, &b, &x, &y); ^