View Compilation Error

0_0_20927129_14675.cpp: In function 'int solve(int, int, int, int)':
0_0_20927129_14675.cpp:19:31: error: 'query' was not declared in this scope
   int temp=query(l,n,s,t,0,mid);
                               ^
0_0_20927129_14675.cpp: In function 'int main()':
0_0_20927129_14675.cpp:47:14: error: 'build' was not declared in this scope
   build(1,n,0);
              ^