View Compilation Error

0_0_39241650_10422.cpp:4:7: error: 'n' was not declared in this scope
    4 | int a[n];
      |       ^
0_0_39241650_10422.cpp: In function 'int main()':
0_0_39241650_10422.cpp:43:17: error: 'a' was not declared in this scope
   43 |          memset(a,0,sizeof(a));
      |                 ^