Compilare: user.cpp: In function ‘int main()’: user.cpp:11:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%d", &n, &m); ^ user.cpp:14:34: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &v[i][j]); ^ user.cpp:53:19: warning: ‘cate’ may be used uninitialized in this function [-Wmaybe-uninitialized] cate+=nr; ^ user.cpp:53:19: warning: ‘nr’ may be used uninitialized in this function [-Wmaybe-uninitialized]