View Compilation Error

0_0_32957127_8550.cpp: In function 'int main()':
0_0_32957127_8550.cpp:13:3: error: 'sum' was not declared in this scope
   sum=0;
   ^
0_0_32957127_8550.cpp:14:7: error: 'i' was not declared in this scope
   for(i=n,j=2;i>=2;i--,j=j+2) sum+=j*1.0/i;  
       ^
0_0_32957127_8550.cpp:14:11: error: 'j' was not declared in this scope
   for(i=n,j=2;i>=2;i--,j=j+2) sum+=j*1.0/i;  
           ^