Update construct-binary-tree-from-preorder-and-postorder-traversal.cpp

kamyu104 · web-flow · commit cc896422b7c3 · 2018-08-19T20:49:51.000+08:00
diff --git a/C++/construct-binary-tree-from-preorder-and-postorder-traversal.cpp b/C++/construct-binary-tree-from-preorder-and-postorder-traversal.cpp
@@ -52,7 +52,7 @@ class Solution2 {
             return nullptr;
         }
         auto node = new TreeNode(pre[pre_s]);
-        if (pre_s + 1 < pre_e) {
+        if (pre_e - pre_s > 1) {
             auto left_tree_size = post_entry_idx_map.at(pre[pre_s + 1]) - post_s + 1;         
             node->left = constructFromPrePostHelper(pre, pre_s + 1, pre_s + 1 + left_tree_size, 
                                                     post, post_s, post_s + left_tree_size,

Original file line number	Diff line number	Diff line change
`@@ -52,7 +52,7 @@ class Solution2 {`
`52`	`52`	`return nullptr;`
`53`	`53`	`}`
`54`	`54`	`auto node = new TreeNode(pre[pre_s]);`
`55`		`- if (pre_s + 1 < pre_e) {`
	`55`	`+ if (pre_e - pre_s > 1) {`
`56`	`56`	`auto left_tree_size = post_entry_idx_map.at(pre[pre_s + 1]) - post_s + 1;`
`57`	`57`	`node->left = constructFromPrePostHelper(pre, pre_s + 1, pre_s + 1 + left_tree_size,`
`58`	`58`	`post, post_s, post_s + left_tree_size,`