Compilare: user.cpp: In function ‘int main()’: user.cpp:6:21: warning: variable ‘c’ set but not used [-Wunused-but-set-variable] char ch[100][100], c; ^ user.cpp:11:21: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &n); ^ user.cpp:12:21: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &m); ^