View Compilation Error

0_0_38641092_28847.cpp: In function 'int main()':
0_0_38641092_28847.cpp:16:13: error: 'f' was not declared in this scope
             f[j]= max(f[j],f[j-v[i-1]]+w[i-1]);
             ^
0_0_38641092_28847.cpp:17:13: error: 'f' was not declared in this scope
       cout<<f[c]<<endl;
             ^