View Compilation Error

0_0_29862856_14662.cpp:9:1: error: 'a' does not name a type
 a[i]:0-n,a[n]=L
 ^
0_0_29862856_14662.cpp: In function 'int main()':
0_0_29862856_14662.cpp:18:4: error: 'sum' was not declared in this scope
    sum[0] = 0;
    ^
0_0_29862856_14662.cpp:19:10: error: base operand of '->' is not a pointer
    n: i:1->n
          ^
0_0_29862856_14662.cpp: In function 'int main()':
0_0_29862856_14662.cpp:216:5: error: redefinition of 'int main()'
 int main() {
     ^
0_0_29862856_14662.cpp:17:5: note: 'int main()' previously defined here
 int main(){
     ^