View Compilation Error

0_0_17133246_14236.cpp: In member function 'long long int Calc::dfs(int, int, int, int)':
0_0_17133246_14236.cpp:16:42: error: 'pow' was not declared in this scope
    if(pre==1) return pow(10,(double)pos+1)+dp[pos];
                                          ^