View Compilation Error

0_0_36352609_410.cpp: In function 'void dfs1(int, int)':
0_0_36352609_410.cpp:29:28: error: 'a' was not declared in this scope
  for(int i = head[x];i;i = a[i].ne) {
                            ^
0_0_36352609_410.cpp: In function 'int main()':
0_0_36352609_410.cpp:129:11: error: invalid conversion from 'int' to 'll* {aka long long int*}' [-fpermissive]
   add(x, y);
           ^
0_0_36352609_410.cpp:129:11: error: too few arguments to function 'void add(ll*, int, ll)'
0_0_36352609_410.cpp:63:6: note: declared here
 void add(ll s[], int x, ll k) {
      ^
0_0_36352609_410.cpp:130:11: error: invalid conversion from 'int' to 'll* {aka long long int*}' [-fpermissive]
   add(y, x);
           ^
0_0_36352609_410.cpp:130:11: error: too few arguments to function 'void add(ll*, int, ll)'
0_0_36352609_410.cpp:63:6: note: declared here
 void add(ll s[], int x, ll k) {
      ^