View Compilation Error

0_0_38605496_14135.cpp: In function 'long long int dfs(long long int, long long int)':
0_0_38605496_14135.cpp:9:11: error: 'j' was not declared in this scope
     if(d==j) return !x;
           ^
0_0_38605496_14135.cpp: In function 'int main()':
0_0_38605496_14135.cpp:24:13: error: 'j' was not declared in this scope
         for(j=0;(1<<j)<=n;j++){
             ^
0_0_38605496_14135.cpp:25:20: error: 'dp' was not declared in this scope
             memset(dp,-1,sizeof(dp));
                    ^~
0_0_38605496_14135.cpp:26:24: error: 'pos' was not declared in this scope
             (res+=(dfs(pos-1,1)*(1<<j)%mod)*(n+1-(1<<j))%mod)%=mod;
                        ^~~
0_0_38605496_14135.cpp:26:24: note: suggested alternative: 'pow'
             (res+=(dfs(pos-1,1)*(1<<j)%mod)*(n+1-(1<<j))%mod)%=mod;
                        ^~~
                        pow