View Compilation Error

0_0_38933876_22617.cpp:13:41: error: conflicting declaration 'long long int a'
   13 | long long n,lsttim,lstpos,curtim,curpos,a=0;//hdusb
      |                                         ^
0_0_38933876_22617.cpp:6:2: note: previous declaration as 'node a [10001]'
    6 | }a[10001];
      |  ^
0_0_38933876_22617.cpp: In function 'int main()':
0_0_38933876_22617.cpp:46:9: error: lvalue required as increment operand
   46 |         a++;
      |         ^