Main.cc: In function 'int main()':
Main.cc:9:6: error: conflicting declaration 'int a'
int a=1;
^
Main.cc:6:12: note: previous declaration as 'long long int a [(n + 1)]'
long long a[n+1];
^
Main.cc:11:15: error: invalid operands of types 'long long int' and 'long long int [(n + 1)]' to binary 'operator*'
a[i]=a[i-1]*a;
^
Main.cc:12:4: error: lvalue required as increment operand
a++;
^