/in/foo.cc: In function 'void DFS1(int)':
/in/foo.cc:36:19: error: 'g1' was not declared in this scope
     for(int k=0;k<g1[i].size();k++)
                   ^~
/in/foo.cc:41:5: error: 'S' was not declared in this scope
     S[++top]=i;
     ^
/in/foo.cc:41:9: error: 'top' was not declared in this scope
     S[++top]=i;
         ^~~
/in/foo.cc: In function 'void DFS2(int)':
/in/foo.cc:46:5: error: 'scc' was not declared in this scope
     scc[i]=sccn;
     ^~~
/in/foo.cc:46:12: error: 'sccn' was not declared in this scope
     scc[i]=sccn;
            ^~~~
/in/foo.cc:47:19: error: 'g2' was not declared in this scope
     for(int k=0;k<g2[i].size();k++)
                   ^~
/in/foo.cc: In function 'void solve()':
/in/foo.cc:60:12: error: 'scc' was not declared in this scope
     memset(scc,0,sizeof(scc));
            ^~~
/in/foo.cc:62:15: error: 'S' was not declared in this scope
        if(scc[S[i]]==0) { sccn++; DFS2(S[i]);}
               ^
/in/foo.cc:62:27: error: 'sccn' was not declared in this scope
        if(scc[S[i]]==0) { sccn++; DFS2(S[i]);}
                           ^~~~
/in/foo.cc:64:19: error: 'sccn' was not declared in this scope
     printf("%d\n",sccn);    
                   ^~~~