LeetCode: Minimum Depth of Binary Tree

C++ Solution:

Queue approach:

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struct DATA{ TreeNode* node; int level; DATA(TreeNode* n, int l):node(n),level(l){} }; class Solution { public: int minDepth(TreeNode* root) { queue< DATA > que; if(!root) return 0; que.push(DATA(root,1)); while(!que.empty()){ DATA current=que.front();//in java, pop() will return element, in c++, not que.pop(); if(!current.node->left && !current.node->right) return current.level; if(current.node->left) //not sure whether DATA() is right for initialization an object que.push(DATA(current.node->left, current.level+1)); if(current.node->right) que.push(DATA(current.node->right, current.level+1)); } } };

Reference:
1. recursion approach: https://helloacm.com/coding-exercise-minimum-depth-of-binary-tree-c-online-judge/
http://blog.theliuy.com/minimum-depth-of-binary-tree/
2. queues approach: http://yucoding.blogspot.com/2013/01/leetcode-question-55-minimum-depth-of.html

JAVA Solution:
Reference: http://gongxuns.blogspot.com/2012/12/leetcode-minimum-depth-of-binary-tree.html