View Compilation Error

0_0_24247709_27698.cpp: In function 'int main()':
0_0_24247709_27698.cpp:21:32: error: 'a' was not declared in this scope
             printf("0 %d %d\n",a[0],a[n - 1]);
                                ^
0_0_24247709_27698.cpp:30:20: error: 'a' was not declared in this scope
             sum -= a[i];
                    ^
0_0_24247709_27698.cpp:36:33: error: 'a' was not declared in this scope
         printf("%d %d %d\n",ans,a[l],a[id]);
                                 ^