[Java] Java数据结构-HashMap详解

static <k,v> treenode<k,v> rotateleft(treenode<k,v> root,
             treenode<k,v> p) {
    treenode<k,v> r, pp, rl;
    if (p != null && (r = p.right) != null) {
    if ((rl = p.right = r.left) != null)
      rl.parent = p;
    if ((pp = r.parent = p.parent) == null)
      (root = r).red = false;
    else if (pp.left == p)
      pp.left = r;
    else
      pp.right = r;
    r.left = p;
    p.parent = r;
    }
    return root;
  }

static <k,v> treenode<k,v> rotateright(treenode<k,v> root,
            treenode<k,v> p) {
    treenode<k,v> l, pp, lr;
    if (p != null && (l = p.left) != null) {
    if ((lr = p.left = l.right) != null)
      lr.parent = p;
    if ((pp = l.parent = p.parent) == null)
      (root = l).red = false;
    else if (pp.right == p)
      pp.right = l;
    else
      pp.left = l;
    l.right = p;
    p.parent = l;
    }
    return root;
  }

static <k,v> treenode<k,v> balanceinsertion(treenode<k,v> root,
              treenode<k,v> x) {
    x.red = true;
    for (treenode<k,v> xp, xpp, xppl, xppr;;) {
    if ((xp = x.parent) == null) {
      x.red = false;
      return x;
    }
    else if (!xp.red || (xpp = xp.parent) == null) //①
      return root;
    if (xp == (xppl = xpp.left)) {
      if ((xppr = xpp.right) != null && xppr.red) { //②
      xppr.red = false;
      xp.red = false;
      xpp.red = true;
      x = xpp;
      }
      else {
      if (x == xp.right) { //③
        root = rotateleft(root, x = xp);
        xpp = (xp = x.parent) == null ? null : xp.parent;
      }
      if (xp != null) { //④
        xp.red = false;
        if (xpp != null) {
        xpp.red = true;
        root = rotateright(root, xpp);
        }
      }
      }
    }
    else {
      if (xppl != null && xppl.red) { //②
      xppl.red = false;
      xp.red = false;
      xpp.red = true;
      x = xpp;
      }
      else {
      if (x == xp.left) {  //⑤
        root = rotateright(root, x = xp);
        xpp = (xp = x.parent) == null ? null : xp.parent;
      }
      if (xp != null) {  //⑥
        xp.red = false;
        if (xpp != null) {
        xpp.red = true;
        root = rotateleft(root, xpp);
        }
      }
      }
    }
    }
  }