View Compilation Error

0_0_37300848_23652.cpp: In function 'int main()':
0_0_37300848_23652.cpp:10:8: error: conflicting declaration 'int* a'
   int *a = new int[n];
        ^
0_0_37300848_23652.cpp:5:13: note: previous declaration as 'int a'
     int n,i,a, sum;
             ^
0_0_37300848_23652.cpp:14:20: error: invalid types 'int[int]' for array subscript
    scanf("%d", &a[i]);
                    ^
0_0_37300848_23652.cpp:16:14: error: invalid types 'int[int]' for array subscript
    sum += a[i];
              ^
0_0_37300848_23652.cpp:20:22: error: invalid types 'int[int]' for array subscript
    scanf("%d\n", &a[i]);
                      ^
0_0_37300848_23652.cpp:21:19: error: invalid types 'int[int]' for array subscript
    sum = sum + a[i];
                   ^