View Compilation Error

0_0_21647532_3554.cpp:11:8: error: 'maxn' was not declared in this scope
 Node a[maxn];
        ^
0_0_21647532_3554.cpp: In function 'bool cmp(Node, Node)':
0_0_21647532_3554.cpp:16:11: error: a function-definition is not allowed here before '{' token
 int main(){
           ^
0_0_21647532_3554.cpp:42:1: error: expected '}' at end of input
 }
 ^