View Compilation Error

0_0_33525443_32676.cpp:10:15: error: uninitialized const 'f' [-fpermissive]
 constexpr int f[maxn + 10], invf[maxn + 10];
               ^
0_0_33525443_32676.cpp:10:29: error: uninitialized const 'invf' [-fpermissive]
 constexpr int f[maxn + 10], invf[maxn + 10];
                             ^
0_0_33525443_32676.cpp: In function 'void init()':
0_0_33525443_32676.cpp:34:7: error: assignment of read-only location 'f[0]'
  f[0] = 1; 
       ^
0_0_33525443_32676.cpp:37:8: error: assignment of read-only location 'f[i]'
   f[i] = 1ll * f[i - 1] * i % mod;
        ^
0_0_33525443_32676.cpp:39:13: error: assignment of read-only location 'invf[100010]'
  invf[maxn] = ksm(f[maxn], mod - 2, mod);
             ^
0_0_33525443_32676.cpp:42:11: error: assignment of read-only location 'invf[i]'
   invf[i] = 1ll * invf[i + 1] * (i + 1) % mod;
           ^