/in/foo.cc: In function 'void dfs(int, int, int)':
/in/foo.cc:28:10: error: expected unqualified-id before '[' token
  for(auto[i,j]:v[x])if(i^f)dfs(i,x,j);
          ^
/in/foo.cc:28:10: error: expected ';' before '[' token
/in/foo.cc:28:11: error: 'i' was not declared in this scope
  for(auto[i,j]:v[x])if(i^f)dfs(i,x,j);
           ^
/in/foo.cc:28:13: error: 'j' was not declared in this scope
  for(auto[i,j]:v[x])if(i^f)dfs(i,x,j);
             ^
/in/foo.cc: In lambda function:
/in/foo.cc:28:15: error: expected '{' before ':' token
  for(auto[i,j]:v[x])if(i^f)dfs(i,x,j);
               ^
/in/foo.cc: In function 'void dfs(int, int, int)':
/in/foo.cc:28:15: error: expected ';' before ':' token
/in/foo.cc:28:15: error: expected primary-expression before ':' token
/in/foo.cc:28:15: error: expected ')' before ':' token
/in/foo.cc:28:15: error: expected primary-expression before ':' token
/in/foo.cc: In function 'void calc(int, int)':
/in/foo.cc:43:10: error: expected unqualified-id before '[' token
  for(auto[i,j]:v[x])if(i^f)calc(i,x),d[x]+=d[i];
          ^
/in/foo.cc:43:10: error: expected ';' before '[' token
/in/foo.cc:43:11: error: 'i' was not declared in this scope
  for(auto[i,j]:v[x])if(i^f)calc(i,x),d[x]+=d[i];
           ^
/in/foo.cc:43:13: error: 'j' was not declared in this scope
  for(auto[i,j]:v[x])if(i^f)calc(i,x),d[x]+=d[i];
             ^
/in/foo.cc: In lambda function:
/in/foo.cc:43:15: error: expected '{' before ':' token
  for(auto[i,j]:v[x])if(i^f)calc(i,x),d[x]+=d[i];
               ^
/in/foo.cc: In function 'void calc(int, int)':
/in/foo.cc:43:15: error: expected ';' before ':' token
/in/foo.cc:43:15: error: expected primary-expression before ':' token
/in/foo.cc:43:15: error: expected ')' before ':' token
/in/foo.cc:43:15: error: expected primary-expression before ':' token
/in/foo.cc: In function 'int main()':
/in/foo.cc:61:8: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   mid=L+r>>1;
       ~^~