1 #include <iostream> 2 #include <cstdlib> 3 using namespace std; 4 struct node 5 { 6 int v; 7 int df; 8 node * left_c; 9 node * right_c; 10 }; 11 void right_rotate(node *&ptr) 12 { 13 if (ptr->right_c->df==-1) 14 { 15 node * child = ptr->right_c; 16 ptr->right_c = child ->left_c; 17 child ->left_c = ptr; 18 ptr->df = 0; 19 child->df = 0; 20 ptr = child; 21 } 22 else 23 { 24 node * child = ptr->right_c; 25 node * g_child = child ->left_c; 26 child ->left_c = g_child ->right_c; 27 ptr->right_c = g_child -> left_c; 28 g_child->left_c = ptr; 29 g_child->right_c = child; 30 switch(g_child->df) 31 { 32 case 0:ptr->df = 0;child->df =0;break; 33 case 1:ptr->df = 0; child->df = -1;g_child->df = 0;break; 34 case -1:ptr->df = 1; child->df = 0;g_child->df = 0;break; 35 } 36 ptr = g_child; 37 } 38 } 39 void left_rotate(node *&ptr) 40 { 41 if (ptr->left_c->df==1) // LL型旋转 42 { 43 // ptr 的左二子成为老子 ptr成为其右儿子 44 node * child = ptr->left_c; 45 ptr->left_c = child ->right_c; 46 child ->right_c = ptr; 47 ptr->df = 0; 48 child->df = 0; 49 ptr = child; 50 } 51 else // LR型旋转 52 { 53 node * child = ptr->left_c; // L儿子 54 node * g_child = child ->right_c; // LR 孙子 55 56 // 孙子的两个儿子 根据 二叉查找树定义 分别给 child 和 ptr 57 child ->right_c = g_child ->left_c; 58 ptr->left_c = g_child -> right_c; 59 //孙子成为老子 60 g_child->right_c = ptr; 61 g_child->left_c = child; 62 //根据孙子的df调整各点 63 switch(g_child->df) 64 { 65 case 0:ptr->df = 0;child->df =0;break; 66 case -1:ptr->df = 0; child->df = 1;g_child->df = 0;break; 67 case 1:ptr->df = -1; child->df = 0;g_child->df = 0;break; 68 } 69 ptr = g_child; 70 } 71 } 72 void avl_insert(node * &ptr ,int t,bool &if_b) 73 { 74 if (ptr == NULL) // 新节点 75 { 76 if_b = false; 77 ptr = (node *)malloc(sizeof(node)); 78 ptr->df = 0; 79 ptr->left_c = NULL; 80 ptr->right_c = NULL; 81 ptr->v = t; 82 } 83 else if (t > ptr->v) // 与左子树完全对称 84 { 85 avl_insert(ptr->right_c,t,if_b); 86 if (!if_b) 87 { 88 switch(ptr->df) 89 { 90 case 0:ptr->df = -1;break; 91 case 1:ptr->df = 0;if_b = true; break; 92 case -1:right_rotate(ptr);if_b = true;break; 93 } 94 } 95 } 96 else if (t < ptr->v) // 在左子树中加入 97 { 98 avl_insert(ptr->left_c,t,if_b); 99 if (!if_b) 100 { 101 switch(ptr->df) 102 { 103 case 0:ptr->df = 1;break;//不平衡 104 case -1:ptr->df = 0;if_b = true; break; //恰好调节平衡 105 case 1:left_rotate(ptr);if_b = true;break; //旋转后调节平衡 106 } 107 } 108 } 109 else // 找到元素 110 { 111 cout <<t <<"cunzai"<<endl; 112 if_b = true; 113 return; 114 } 115 } 116 void proorder(node * ptr) //中序遍历 117 { 118 if (ptr ==NULL) return; 119 proorder(ptr->left_c); 120 cout << ptr->v <<" "; 121 proorder(ptr->right_c); 122 } 123 int main() 124 { 125 int N; 126 cin >> N; 127 node* root = NULL; 128 bool if_b = false; 129 for (int i = 1 ; i<=N; i++) 130 { 131 int x; 132 cin >> x; 133 if_b = false; 134 avl_insert(root,x,if_b); 135 } 136 proorder(root); 137 cout <<endl; 138 }