View Compilation Error

0_0_27694199_23036.c:21:1: error: expected identifier or '(' before '/' token
 //x = n*log10( (double)n );
 ^
0_0_27694199_23036.c:22:1: error: expected identifier or '(' before '/' token
 //x = (long long)x;
 ^
0_0_27694199_23036.c:23:1: error: expected identifier or '(' before '/' token
 //x = (int)pow(10,x);
 ^
0_0_27694199_23036.c:24:1: error: expected identifier or '(' before '/' token
 //printf("%.0lf\n",x);
 ^