View Compilation Error

0_0_18841444_27954.c: In function 'main':
0_0_18841444_27954.c:21:3: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
   for (int j = i-1; j>=0; j--)
   ^
0_0_18841444_27954.c:21:3: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code