View Compilation Error

0_0_38769468_11183.cpp:1:1: error: 'a' does not name a type
    1 | a[n+1] = -1;
      | ^
0_0_38769468_11183.cpp:2:7: error: expected constructor, destructor, or type conversion before '(' token
    2 | memset(dp, 0, sizeof(dp));
      |       ^
0_0_38769468_11183.cpp:3:7: error: expected constructor, destructor, or type conversion before '(' token
    3 | memset(dp, 0, sizeof(dp));
      |       ^