View Compilation Error

0_0_28130055_15311.cpp: In member function 'int SegmentTree::query(int, int, int, int, int)':
0_0_28130055_15311.cpp:69:15: error: 'find' was not declared in this scope
    if(find(mid)==find(mid+1))s--;
               ^
0_0_28130055_15311.cpp: In function 'int main()':
0_0_28130055_15311.cpp:101:22: error: 'struct SegmentTree' has no member named 'Query'
     printf("%d\n",ST.Query(1,n,x,y,1));
                      ^