View Compilation Error

0_0_37681198_13196.cpp: In function 'int dfs(int, bool, bool)':
0_0_37681198_13196.cpp:13:16: error: 'a' was not declared in this scope
  int len=limit?a[pos]:9,ans=0;
                ^
0_0_37681198_13196.cpp:17:3: error: 'ans' was not declared in this scope
   ans+=dfs(pos-1,i==6,limit&&i==len);
   ^
0_0_37681198_13196.cpp:20:16: error: 'ans' was not declared in this scope
   dp[pos][sta]=ans;
                ^
0_0_37681198_13196.cpp:21:9: error: 'ans' was not declared in this scope
  return ans;
         ^
0_0_37681198_13196.cpp: In function 'int real_main(int)':
0_0_37681198_13196.cpp:27:3: error: 'a' was not declared in this scope
   a[++tot]=x%10;
   ^