View Compilation Error

0_0_16909337_29246.c: In function 'main':
0_0_16909337_29246.c:6:2: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
  for(int i=1;i<1000000;i++){
  ^
0_0_16909337_29246.c:6:2: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
0_0_16909337_29246.c:8:3: error: unknown type name 'bool'
   bool ok=1;
   ^