Compilare: user.cpp: In function ‘int main()’: user.cpp:9:54: warning: left operand of comma operator has no effect [-Wunused-value] for(i=n/2 , j=n/2+1 , a=n+n/2 , b=n+n/2+2 ; i>=1 , j<=n , a>n , b<=n*2+1 ; i-- , j++ , a-- , b++){ ^ user.cpp:9:61: warning: right operand of comma operator has no effect [-Wunused-value] for(i=n/2 , j=n/2+1 , a=n+n/2 , b=n+n/2+2 ; i>=1 , j<=n , a>n , b<=n*2+1 ; i-- , j++ , a-- , b++){ ^ user.cpp:9:68: warning: right operand of comma operator has no effect [-Wunused-value] for(i=n/2 , j=n/2+1 , a=n+n/2 , b=n+n/2+2 ; i>=1 , j<=n , a>n , b<=n*2+1 ; i-- , j++ , a-- , b++){ ^ user.cpp:16:56: warning: left operand of comma operator has no effect [-Wunused-value] for(i=n/2 , j=n/2+2 , a=n+n/2+1 , b=n+n/2+2 ; i>=1 , j<=n , a>n , b<=2*n+1 ; i-- , j++ , a-- , b++){ ^ user.cpp:16:63: warning: right operand of comma operator has no effect [-Wunused-value] for(i=n/2 , j=n/2+2 , a=n+n/2+1 , b=n+n/2+2 ; i>=1 , j<=n , a>n , b<=2*n+1 ; i-- , j++ , a-- , b++){ ^ user.cpp:16:70: warning: right operand of comma operator has no effect [-Wunused-value] for(i=n/2 , j=n/2+2 , a=n+n/2+1 , b=n+n/2+2 ; i>=1 , j<=n , a>n , b<=2*n+1 ; i-- , j++ , a-- , b++){ ^