1 public class redbalcktree { 2 3 private class Node{ 4 private int val; 5 private int key; 6 boolean color; //black true 7 private Node left,right,p; 8 private int N; //the number of the all nodes of its child nodes and itself 9 //private int num;//the number 10 public Node(int val,int key){ 11 this.val = val; this.key = key; 12 } 13 14 } 15 16 Node root; 17 18 private void leftrotation(Node x){ 19 Node y = x.right; 20 x.right = y.left; 21 if(y.left != null){ 22 y.left.p = x; 23 } 24 y.p = x.p; 25 if(x.p == null){ 26 root = y; 27 } 28 else if(x == x.p.left){ 29 x.p.left = y; 30 } 31 else{x.p.right = y;} 32 y.left = x; 33 x.p = y; 34 } 35 36 private void rightrotation(Node y){ 37 Node x = y.left; 38 y.left = x.right; 39 if(x.right != null){ 40 x.right.p = y; 41 } 42 x.p = y.p; 43 if(y.p == null){ 44 root = x; 45 } 46 else if(y == y.p.left){ 47 y.p.left = x; 48 } 49 else{y.p.right = x;} 50 x.right = y; 51 y.p = x; 52 } 53 54 public void insert(int val,int key){ 55 Node y = null; 56 Node x = root; 57 Node z = new Node(val,key); 58 if(x == null){root = z;} 59 while(x != null){ 60 y = x; 61 if(z.key < x.key){ 62 x = x.left; 63 } 64 else{x = x.right;} 65 } 66 z.p = y; 67 if(z.key < y.key){ 68 y.left = z; 69 } 70 else{y.right = z;} 71 z.left = null; 72 z.right = null; 73 z.color = false; 74 inseretfix(z); 75 76 } 77 78 private void inseretfix(Node z){ 79 Node y; 80 while (z.p.color == false){ 81 if(z.p == z.p.p.left){ 82 y = z.p.p.right; 83 if(y.color == false){ //case 1,both z.p and y(uncle) are red 84 z.p.color = true; 85 y.color = true; 86 z.p.p.color = false; 87 z= z.p.p; 88 continue; 89 } 90 else if(z == z.p.right){ //case 2, z.p is red,uncle is black,z is right,transfer to case 3 91 z = z.p; 92 leftrotation(z); 93 } 94 z.p.color = true; //case 3, z.p is red,uncle is black,z is left; 95 z.p.p.color = false; 96 rightrotation(z.p.p); 97 } 98 else{ //set y(uncle) and change rotation 99 y = z.p.p.left; 100 if(y.color == false){ //case 1,both z.p and y(uncle) are red 101 z.p.color = true; 102 y.color = true; 103 z.p.p.color = false; 104 z= z.p.p; 105 continue; 106 } 107 else if(z == z.p.right){ //case 2, z.p is red,uncle is black,z is right,transfer to case 3 108 z = z.p; 109 rightrotation(z); 110 } 111 z.p.color = true; //case 3, z.p is red,uncle is black,z is left; 112 z.p.p.color = false; 113 leftrotation(z.p.p); 114 } 115 } 116 root.color = true; 117 } 118 119 private int get(Node x,int key){ 120 if(x == null){ 121 throw new NullPointerException("have't this key"); 122 } 123 124 if(x.key>key){ 125 return get(x.left,key); 126 } 127 else if(x.key < key){ 128 return get(x.right,key); 129 } 130 else{ 131 return x.val; 132 } 133 } 134 135 private void transplant(Node u,Node v){ //substitute u as v 136 if(u.p == null){ 137 root = v; 138 } 139 else if(u == u.p.left){ 140 u.p.left = v; 141 } 142 else { 143 u.p.right = v; 144 } 145 v.p = u.p; 146 } 147 148 private Node deletemin(Node x){ 149 if(x.left == null){return x.right;} 150 x.left = deletemin(x.left); 151 return x; 152 } 153 154 public void delete(int key){ 155 int val = get(root,key); 156 Node z = new Node(val,key); 157 Node x; 158 Node y = z; 159 boolean original = y.color; 160 if(z.left == null){ 161 x = z.right; 162 transplant(z,z.right); 163 } 164 else if(z.right == null){ 165 x = z.left; 166 transplant(z,z.left); 167 } 168 else{ 169 y = deletemin(z.right); // next node after z 170 original = y.color; 171 x = y.right; 172 if(y.p == z){ 173 x.p = y; 174 } 175 else{ 176 transplant(y,y.right); // put y.right on the original y's position 177 y.right = z.right; 178 y.right.p = y; 179 } 180 transplant(z,y); 181 y.left = z.left; 182 y.left.p = y; 183 y.color = z.color; 184 } 185 if(original == true){ 186 deletefix(x); 187 } 188 } 189 190 191 private void deletefix(Node x) { 192 Node other; 193 while ((x.color = true) && (x != root)) { 194 if (x.p.left == x) { 195 other = x.p.right; 196 if (other.color == false) { 197 // Case 1: x's brother is red 198 other.color = true; 199 x.p.color = false; 200 leftrotation(x.p); 201 other = x.p.right; 202 } 203 204 if ((other.left.color == true) && 205 (other.right.color == true) ){ 206 // Case 2: x's black is black and w 's both child are black 207 other.color = false; 208 x = x.p; 209 continue; 210 } else if (other.right.color == true) { 211 // Case 3: transfer to case 4 212 other.left.color = true; 213 other.color = false; 214 rightrotation(other); 215 other = x.p.right; 216 } 217 // Case 4: x's black is black,w's right child is red ,left anyway 218 other.color = x.p.color; 219 x.p.color = true; 220 other.right.color = true; 221 leftrotation(x.p); 222 x = root; 223 break; 224 } 225 else { 226 227 other = x.p.left; 228 if (other.color == false) { 229 // Case 1: x's brother is red 230 other.color = true; 231 x.p.color = false; 232 rightrotation(x.p); 233 other = x.p.right; 234 } 235 236 if ((other.left.color == true) && 237 (other.right.color == true) ){ 238 // Case 2: x's black is black and w 's both child are black 239 other.color = false; 240 x = x.p; 241 continue; 242 } else if (other.right.color == true) { 243 // Case 3: transfer to case 4 244 other.left.color = true; 245 other.color = false; 246 leftrotation(other); 247 other = x.p.right; 248 } 249 // Case 4: x's black is black,w's right child is red ,left anyway 250 other.color = x.p.color; 251 x.p.color = true; 252 other.right.color = true; 253 rightrotation(x.p); 254 x = root; 255 break; 256 } 257 258 } 259 } 260 261 262 263 264 }
