View Compilation Error

0_0_28999432_30388.c: In function 'init':
0_0_28999432_30388.c:9:2: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
  for (int i = 0; i <= n; i++)
  ^
0_0_28999432_30388.c:9:2: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
0_0_28999432_30388.c: At top level:
0_0_28999432_30388.c:23:1: error: expected identifier or '(' before '/' token
 //void join(int a,int b,int v)
 ^