Compilare: user.cpp: In function ‘int main()’: user.cpp:52:20: warning: array subscript has type ‘char’ [-Wchar-subscripts] pfv[a[i][j]] = {i, j}; ^ user.cpp:59:33: warning: array subscript has type ‘char’ [-Wchar-subscripts] v[i] = {v[i].ch, pfv[v[i].ch].x, pfv[v[i].ch].y}; ^ user.cpp:59:49: warning: array subscript has type ‘char’ [-Wchar-subscripts] v[i] = {v[i].ch, pfv[v[i].ch].x, pfv[v[i].ch].y}; ^ user.cpp:39:34: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d%d%d", &p, &n, &m); ^