http://www.cnblogs.com/yangecnu/p/Introduce-Red-Black-Tree.html
http://www.cnblogs.com/maybe2030/p/4715035.html
http://algs4.cs.princeton.edu/33balanced/
http://www.cnblogs.com/yangecnu/p/Introduce-Red-Black-Tree.html
http://www.cnblogs.com/maybe2030/p/4715035.html
http://algs4.cs.princeton.edu/33balanced/