View Compilation Error

0_0_28137313_6138.c: In function 'judge':
0_0_28137313_6138.c:32:2: error: expected expression before '/' token
  //return ret;
  ^
0_0_28137313_6138.c: In function 'main':
0_0_28137313_6138.c:41:2: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
  for(int i=0;i<testnum;i++){
  ^
0_0_28137313_6138.c:41:2: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code