View Compilation Error

0_0_33196694_23653.cpp: In function 'int main()':
0_0_33196694_23653.cpp:28:8: error: 'i' was not declared in this scope
   for (i = 1; i <= n; i++){
        ^
0_0_33196694_23653.cpp:34:8: error: 'i' was not declared in this scope
   for (i = n; i > 0; i--){
        ^