Compilare: user.c: In function ‘main’: user.c:32:36: warning: suggest parentheses around ‘+’ inside ‘>>’ [-Wparentheses] S+=((-2)*((c&(1<<i))>>i+((c&(1<<(n+j)))>>(n+j))%2)+1)*a[i][j]; ^ user.c:14:13: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf (f,"%d",&n); ^ user.c:15:13: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf (f,"%d",&m); ^ user.c:19:15: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&a[i][j]); ^