View Compilation Error

0_0_36690559_32195.cpp: In function 'int main()':
0_0_36690559_32195.cpp:43:44: error: 'j' was not declared in this scope
             ans=(ans+((n*c(n*n-i,n-1)%mod)*j[n*n-n]%mod)*j[n]%mod)%mod;
                                            ^