从零开始Leetcode – Day 15
Count Complete Tree Nodes
https://leetcode.com/problems/count-complete-tree-nodes/
注意直接递归会超时， log(N)
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| var countNodes = function(root) {
if(root ===null){
return 0;
}
var l = leftDepth(root);
var r = rightDepth(root);
if(l =r){
return (Math.pow(2, l)-1);
} else{
return 1 + countNodes(root.left) + countNodes(root.right);
}
};
var leftDepth = function(root){
var h = 0;
while(root !==null){
h++;
root = root.left
}
return h;
};
var rightDepth = function(root){
var h = 0;
while(root !==null){
h++;
root = root.right;
}
return h;
};
|