View Compilation Error

0_0_39537790_8055.cpp: In function 'int main()':
0_0_39537790_8055.cpp:46:34: error: '_pow' was not declared in this scope; did you mean 'pow'?
   46 |         for(int i=0;i<25;++i)    _pow[i]=1<<i;
      |                                  ^~~~
      |                                  pow