View Compilation Error

0_0_24601586_9814.cpp:4:9: error: 'maxn' was not declared in this scope
 int n,a[maxn],ans[maxn];  
         ^
0_0_24601586_9814.cpp:4:19: error: 'maxn' was not declared in this scope
 int n,a[maxn],ans[maxn];  
                   ^
0_0_24601586_9814.cpp: In function 'int getsum(int)':
0_0_24601586_9814.cpp:13:14: error: 'a' was not declared in this scope
         s += a[n];  
              ^
0_0_24601586_9814.cpp: In function 'void add(int)':
0_0_24601586_9814.cpp:21:16: error: 'maxn' was not declared in this scope
     while(x <= maxn)  
                ^
0_0_24601586_9814.cpp:23:11: error: 'a' was not declared in this scope
         ++a[x];  
           ^
0_0_24601586_9814.cpp: In function 'int main()':
0_0_24601586_9814.cpp:33:16: error: 'a' was not declared in this scope
         memset(a,0,sizeof(a));
                ^
0_0_24601586_9814.cpp:34:16: error: 'ans' was not declared in this scope
         memset(ans,0,sizeof(ans));
                ^