Compilare: user.cpp: In function ‘int main()’: user.cpp:113:10: warning: array subscript has type ‘char’ [-Wchar-subscripts] frp[a][b]++; ^ user.cpp:113:13: warning: array subscript has type ‘char’ [-Wchar-subscripts] frp[a][b]++; ^ user.cpp:98:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d ", &n, &m); ^ user.cpp:99:25: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(s, MAXN + 2, in); ^