View Compilation Error

0_0_26521518_16867.cpp:6:11: error: size of array 'a' is not an integral constant-expression
 int a[maxn],b[maxn];
           ^
0_0_26521518_16867.cpp:6:19: error: size of array 'b' is not an integral constant-expression
 int a[maxn],b[maxn];
                   ^
0_0_26521518_16867.cpp:7:22: error: size of array 'edge' is not an integral constant-expression
 vector<int> edge[maxn];
                      ^