Compilare: user.cpp: In function ‘void df(int, int)’: user.cpp:32:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < v[x].size(); j++) ^ user.cpp: In function ‘int main()’: user.cpp:69:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < b.size(); i++) ^ user.cpp:81:13: warning: statement has no effect [-Wunused-value] for (dim; dim <= 10; dim++) ^ user.cpp:43:44: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("psychtraining.in", "r", stdin); ^ user.cpp:44:46: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("psychtraining.out", "w", stdout); ^ user.cpp:46:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:49:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^