View Compilation Error

0_0_17798179_406.cpp: In function 'void getfact()':
0_0_17798179_406.cpp:3:5: error: 'fact' was not declared in this scope
     fact[0]=fact[1]=inv[0]=inv[1]=f[0]=f[1]=1;   
     ^
0_0_17798179_406.cpp:3:21: error: 'inv' was not declared in this scope
     fact[0]=fact[1]=inv[0]=inv[1]=f[0]=f[1]=1;   
                     ^
0_0_17798179_406.cpp:3:35: error: 'f' was not declared in this scope
     fact[0]=fact[1]=inv[0]=inv[1]=f[0]=f[1]=1;   
                                   ^
0_0_17798179_406.cpp:4:21: error: 'n' was not declared in this scope
     for (int i=2;i<=n;i++)  
                     ^
0_0_17798179_406.cpp:6:29: error: 'MOD' was not declared in this scope
         fact[i]=fact[i-1]*i%MOD;  
                             ^