Determine whether a binary tree is a balanced binary tree and a binary tree

Determine whether a binary tree is a balanced binary tree and a binary tree
Question: Determine whether a binary tree is a balanced binary tree

Idea: use recursion to determine whether the depth of left and right subtree is different from 1 to determine whether it is a balanced binary tree.

1 # include <stdio. h> 2 # include "stdafx. h "3 4 struct BinaryTreeNode 5 {6 int m_nValue; 7 BinaryTreeNode * m_pLeft; 8 BinaryTreeNode * m_pRight; 9}; 10 11 BinaryTreeNode * CreateBinaryTreeNode (int value) 12 {13 BinaryTreeNode * pNode = new BinaryTreeNode (); 14 pNode-> m_nValue = value; 15 pNode-> m_pLeft = NULL; 16 pNode-> m_pRight = NULL; 17} 18 19 void ConnectTreeNodes (BinaryTreeNode * pParent, Binary TreeNode * pLeft, BinaryTreeNode * pRight) 20 {21 if (pParent! = NULL) 22 {23 pParent-> m_pLeft = pLeft; 24 pParent-> m_pRight = pRight; 25} 26} 27 28 void PrintTreeNode (BinaryTreeNode * pNode) 29 {30 if (pNode! = NULL) 31 {32 printf ("value of this node is: % d \ n", pNode-> m_nValue); 33 34 if (pNode-> m_pLeft! = NULL) 35 printf ("value of its left child is: % d. \ n ", pNode-> m_pLeft-> m_nValue); 36 else 37 printf (" left child is null. \ n "); 38 39 if (pNode-> m_pRight! = NULL) 40 printf ("value of its right child is: % d. \ n ", pNode-> m_pRight-> m_nValue); 41 else 42 printf (" right child is null. \ n "); 43} 44 else 45 {46 printf (" this node is null. \ n "); 47} 48 printf (" \ n "); 49} 50 51 void PrintTree (BinaryTreeNode * pRoot) 52 {53 PrintTreeNode (pRoot ); 54 55 if (pRoot! = NULL) 56 {57 if (pRoot-> m_pLeft! = NULL) 58 PrintTree (pRoot-> m_pLeft); 59 60 if (pRoot-> m_pRight! = NULL) 61 PrintTree (pRoot-> m_pRight); 62} 63} 64 65 void DestroyTree (BinaryTreeNode * pRoot) 66 {67 if (pRoot! = NULL) 68 {69 BinaryTreeNode * pLeft = pRoot-> m_pLeft; 70 BinaryTreeNode * pRight = pRoot-> m_pRight; 71 72 delete pRoot; 73 pRoot = NULL; 74 75 DestroyTree (pLeft); 76 DestroyTree (pRight ); 77} 78} 79 80 81 // ================ method 1 ====== =====================================82 int TreeDepth (BinaryTreeNode * pRoot) 83 {84 if (pRoot = NULL) 85 return 0; 86 87 int nLeft = TreeDepth (pRoot-> m_pLeft); 88 int nRi Ght = TreeDepth (pRoot-> m_pRight); 89 90 return (nLeft> nRight )? (NLeft + 1): (nRight + 1); 91} 92 93 bool IsBalanced_Solution1 (BinaryTreeNode * pRoot) 94 {95 if (pRoot = NULL) 96 return true; 97 98 int left = TreeDepth (pRoot-> m_pLeft); 99 int right = TreeDepth (pRoot-> m_pRight); 100 int diff = left-right; 101 if (diff> 1 | diff <-1) 102 return false; 103 104 return IsBalanced_Solution1 (pRoot-> m_pLeft) 105 & IsBalanced_Solution1 (pRoot-> m_pRight ); 106} 107 108/ /================================= Method 2 ========================== ========== 109 bool IsBalanced (BinaryTreeNode * pRoot, int * pDepth); 110 111 bool IsBalanced_Solution2 (BinaryTreeNode * pRoot) 112 {113 int depth = 0; 114 return IsBalanced (pRoot, & depth ); 115} 116 117 bool IsBalanced (BinaryTreeNode * pRoot, int * pDepth) 118 {119 if (pRoot = NULL) 120 {121 * pDepth = 0; 122 return true; 123} 124 125 int left, right; 126 if (IsBalanced (pR Oot-> m_pLeft, & left) 127 & IsBalanced (pRoot-> m_pRight, & right) 128 {129 int diff = left-right; 130 if (diff <= 1 & diff> =-1) 131 {132 * pDepth = 1 + (left> right? Left: right); 133 return true; 134} 135} 136 137 return false; 138} 139 140 // not a Complete Binary Tree, however, the balance Binary Tree 141 // 1142 // \ 143 // 2 3144 // \ 145 // 4 5 6146 // 147 // 7148 149 int main () 150 {151 BinaryTreeNode * pNode1 = CreateBinaryTreeNode (1); 152 BinaryTreeNode * pNode2 = CreateBinaryTreeNode (2); 153 BinaryTreeNode * pNode3 = CreateBinaryTreeNode (3 ); 154 BinaryTreeNode * pNode4 = round (4); 155 BinaryTreeNode * pNode5 = round (5); 156 BinaryTreeNode * pNode6 = round (6); 157 BinaryTreeNode * pNode7 = CreateBinaryTreeNode (7 ); 158 ConnectTreeNodes (pNode1, pNode2, pNode3); 159 ConnectTreeNodes (pNode2, pNode4, pNode5); 160 ConnectTreeNodes (pNode3, pNode6, pNode7); 161 162 printf ("Solution1 begins: "); 164 if (IsBalanced_Solution1 (pNode1) 165 printf (" is balanced. \ n "); 166 else167 printf (" not balanced. \ n "); 168 169 printf (" Solution2 begins: "); 170 if (IsBalanced_Solution2 (pNode1) 171 printf (" is balanced. \ n "); 172 else173 printf (" not balanced. \ n "); 174 printf (" \ n "); 175 176 DestroyTree (pNode1); 177 178 179 return 0; 180}