View Compilation Error

0_0_28353761_13599.c:3:1: error: expected identifier or '(' before '/' token
 //const int MAX=100005;
 ^
0_0_28353761_13599.c:4:20: error: expected identifier or '(' before '/' token
 int father[100005];//         https://www.nitacm.com/problem_show.php?pid=361
                    ^
0_0_28353761_13599.c: In function 'main':
0_0_28353761_13599.c:57:3: error: 'flag' undeclared (first use in this function)
   flag=0;
   ^
0_0_28353761_13599.c:57:3: note: each undeclared identifier is reported only once for each function it appears in