View Compilation Error

0_0_32845466_30721.cpp: In function 'int main()':
0_0_32845466_30721.cpp:12:20: error: expected initializer before 'for'
 #define rep(i,a,b) for(int i=a;i<b;i++)
                    ^
0_0_32845466_30721.cpp:22:3: note: in expansion of macro 'rep'
   rep(i, 0, n){
   ^
0_0_32845466_30721.cpp:22:7: error: 'i' was not declared in this scope
   rep(i, 0, n){
       ^
0_0_32845466_30721.cpp:12:32: note: in definition of macro 'rep'
 #define rep(i,a,b) for(int i=a;i<b;i++)
                                ^