/in/foo.cc: In function 'int main()':
/in/foo.cc:30:33: error: 'pow' was not declared in this scope
     cost[1][i] = a[1]*pow(i,b[1]);
                                 ^
/in/foo.cc:35:65: error: 'pow' was not declared in this scope
     cost[i][j] = llmin(cost[i][j],cost[i-1][k]+a[i]*pow(j-k,b[i]));
                                                                 ^