Time: 12 ms (26.80%), Space: 17.7 MB (6.42%) - LeetHub

Author: JanaSabuj

maximum-width-of-binary-tree/maximum-width-of-binary-tree.cpp

@@ -0,0 +1,41 @@
+/**
+ * Definition for a binary tree node.
+ * struct TreeNode {
+ *     int val;
+ *     TreeNode *left;
+ *     TreeNode *right;
+ *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
+ *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
+ *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
+ * };
+ */
+class Solution {
+    unordered_map<unsigned long long int,unsigned long long int> minw, maxw;
+public:
+    void dfs(TreeNode* root, unsigned long long int ht, unsigned long long int w){        
+        // base
+        if(root == NULL)
+            return;
+        
+        // main
+        if(minw.find(ht) == minw.end()){
+            minw[ht] = w;
+            maxw[ht] = w;
+        }else{
+            minw[ht] = min(minw[ht], w);
+            maxw[ht] = max(maxw[ht], w);
+        }
+                        
+        dfs(root->left, ht + 1, 2L * w);
+        dfs(root->right, ht + 1, 2L * w + 1);
+    }
+    int widthOfBinaryTree(TreeNode* root) {
+        dfs(root,0, 1);
+        unsigned long long int ans = 0;
+        for(auto x: minw){
+            ans = max(ans, maxw[x.first] - minw[x.first] + 1);
+        }
+        
+        return ans;
+    }
+};