View Compilation Error

0_0_34443809_20321.c: In function 'max':
0_0_34443809_20321.c:6:2: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
  for(int i=b; i<len; i++) {
  ^
0_0_34443809_20321.c:6:2: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
0_0_34443809_20321.c: In function 'main':
0_0_34443809_20321.c:29:3: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
   for(int k=0; k<n; k++) {
   ^