View Compilation Error

0_0_39326782_23574.c:5:1: error: unknown type name 'using'
    5 | using namespace std;
      | ^~~~~
0_0_39326782_23574.c:5:17: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'std'
    5 | using namespace std;
      |                 ^~~
0_0_39326782_23574.c:12:5: error: variably modified 'root' at file scope
   12 | int root[MAX];
      |     ^~~~
0_0_39326782_23574.c:13:4: error: variably modified 'tree' at file scope
   13 | ll tree[MAX<<5],change[MAX<<5];
      |    ^~~~
0_0_39326782_23574.c:13:17: error: variably modified 'change' at file scope
   13 | ll tree[MAX<<5],change[MAX<<5];
      |                 ^~~~~~
0_0_39326782_23574.c:14:5: error: variably modified 'lc' at file scope
   14 | int lc[MAX<<5],rc[MAX<<5];
      |     ^~
0_0_39326782_23574.c:14:16: error: variably modified 'rc' at file scope
   14 | int lc[MAX<<5],rc[MAX<<5];
      |                ^~