View Compilation Error

0_0_28322350_22997.cpp: In function 'int main()':
0_0_28322350_22997.cpp:12:3: error: 'f' was not declared in this scope
   f[i]=1;//初始化 
   ^
0_0_28322350_22997.cpp:21:5: error: 'f' was not declared in this scope
     f[j]=min(f[j],f[j-w[i]]*v[i]);//失败率越小越好 
     ^
0_0_28322350_22997.cpp:24:25: error: 'f' was not declared in this scope
   printf("%.1lf%%\n",(1-f[c])*100);
                         ^