版权声明:本文为博主原创文章,未经博主允许不得转载。 https://blog.csdn.net/muzhixi/article/details/87968468
首先找到根结点,然后将先序遍历与中序遍历数组切割为两部分,分治为左右子树重建问题。
public TreeNode reConstructBinaryTree(int [] pre,int [] in) {
return reConstructBinaryTreeII(pre,0,pre.length,in,0,in.length);
}
public static TreeNode reConstructBinaryTreeII(int[] pre,int preStart,int preStop,int[] in,int inStart,int inStop){
if(preStart>=preStop||inStart>=inStop) return null;
TreeNode root=new TreeNode(pre[preStart]);
for(int i=inStart;i<inStop;i++){
if(in[i]==pre[preStart]){
root.left=reConstructBinaryTreeII(pre,preStart+1,preStart+1+i-inStart,in,inStart,i);
root.right=reConstructBinaryTreeII(pre,preStart+1+i-inStart,preStop,in,i+1,inStop);
break;
}
}
return root;
}