View Compilation Error

0_0_19172170_23347.cpp: In function 'int main()':
0_0_19172170_23347.cpp:13:12: error: conflicting declaration 'int a [100]'
   int a[100]={0},i,k=0;
            ^
0_0_19172170_23347.cpp:8:7: note: previous declaration as 'int a'
   int a,b,s;
       ^
0_0_19172170_23347.cpp:19:8: error: invalid types 'int[int]' for array subscript
     a[i]=s;
        ^
0_0_19172170_23347.cpp:22:7: error: invalid types 'int[int]' for array subscript
    a[i]=s%m;
       ^
0_0_19172170_23347.cpp:26:19: error: invalid types 'int[int]' for array subscript
    printf("%d",a[i]);
                   ^