View Compilation Error

0_0_34121000_27246.c: In function 'main':
0_0_34121000_27246.c:10:5: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
     for(int i=n-1; i>=1; i--)
     ^
0_0_34121000_27246.c:10:5: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code