View Compilation Error

0_0_38737054_2558.cpp: In function 'void solve()':
0_0_38737054_2558.cpp:16:24: error: 'fpow' was not declared in this scope
   16 |         long long b2 = fpow(b, mod - 2);
      |                        ^~~~
0_0_38737054_2558.cpp:25:42: error: 'c' was not declared in this scope
   25 |                 ans = (ans + cur % mod * c(n, i) % mod * sorce % mod) % mod;
      |                                          ^