View Compilation Error

0_0_26902982_21690.c: In function 'Init':
0_0_26902982_21690.c:14:2: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
  for(int i=0;i<len;i++){
  ^
0_0_26902982_21690.c:14:2: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
0_0_26902982_21690.c: In function 'manacher':
0_0_26902982_21690.c:24:2: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
  for(int i=1;i<len;i++){
  ^