#pragma once
#include #include #include typedef char datatype;
typedef struct btreenode btreenode;
btreenode * createnode(datatype data)
btreenode * createtree(datatype pre, int size, int *index)
if (pre[*index] == '#')
btreenode *proot = createnode(pre[*index]);
(*index)++;
proot->pleft = createtree(pre, size, index);
proot->pright = createtree(pre, size, index);
return proot;
}int getheightr(btreenode *proot)
int left = getheightr(proot->pleft);
int right = getheightr(proot->pright);
return (left > right ? left : right) + 1;
}void getheight(btreenode *proot, int *pheight)
int left, right;
getheight(proot->pleft, &left);
getheight(proot->pright, &right);
*pheight = (left > right ? left : right) + 1;
}int max(int a, int b, int c)
if (b >= a && b >= c)
return c;
}int 找最遠距離(btreenode *proot)
int leftheight = getheightr(proot->pleft);
int rightheight = getheightr(proot->pright);
int rootpath = leftheight + rightheight;
int leftpath = 找最遠距離(proot->pleft);
int rightpath = 找最遠距離(proot->pright);
return max(rootpath, leftpath, rightpath);
}int 找最遠距離優化版(btreenode *proot, int *pheight)
int leftheight, rightheight;
int leftpath = 找最遠距離優化版(proot->pleft, &leftheight);
int rightpath = 找最遠距離優化版(proot->pright, &rightheight);
int rootpath = leftheight + rightheight;
*pheight = (leftheight > rightheight ? leftheight : rightheight) + 1;
return max(rootpath, leftpath, rightpath);
}void mirror(btreenode *proot)
// 可加可不加（加了效率更好)
if (proot->pleft == null && proot->pright == null)
btreenode *pleft = proot->pleft;
proot->pleft = proot->pright;
proot->pright = pleft;
mirror(proot->pleft);
mirror(proot->pright);
}int isbalance(btreenode *proot)
int left = isbalance(proot->pleft);
if (left == 0)
int right = isbalance(proot->pright);
if (right == 0)
// 左右子樹都平衡
int lefth = getheightr(proot->pleft);
int righth = getheightr(proot->pright);
if (lefth - righth >= -1 && lefth - righth <= 1)
else
}btreenode * find(btreenode *proot, btreenode *node)
if (proot == node)
btreenode *pfound = find(proot->pleft, node);
if (pfound != null)
return find(proot->pright, node);
}btreenode * 找最近公共祖先(btreenode *proot, btreenode *n1, btreenode *n2)
if (pn1rightfound != null && pn2rightfound != null)
if (pn1leftfound != null && pn2rightfound != null)
if (pn2leftfound != null && pn1rightfound != null)
if (n1 == proot && (pn2leftfound || pn2rightfound))
if (n2 == proot && (pn1leftfound || pn1rightfound))
return null;
}btreenode * createtreebypreorderandinorder(
char preorder, int preordersize,
char inorder, int inordersize)
char rootchar = preorder[0]; // 這裡越界了麼？
int i;
for (i = 0; i < inordersize; i++)
} if (i == inordersize)
btreenode *proot = createnode(rootchar);
proot->pleft = createtreebypreorderandinorder(
preorder + 1, i,
inorder, i);
proot->pright = createtreebypreorderandinorder(
preorder + 1 + i, preordersize - i - 1,
inorder + 1 + i, inordersize - i - 1);
return proot;
}void test()
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二叉樹的基本概念就不多說了 如下 binarytree.c pragma once include include include include typedef char btdatatype typedef struct binarytreenode btnode a是乙個前序遍歷的陣列 二叉樹...
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node rebuildbtree int preorder,int lenth,int inorder,int start,int end if root left if root right return root bool hascommonroot node roo1,node roo2 r...