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| class Solution {
public:
Node* connect(Node* root) {
queue<Node*> q;
if(root)
q.push(root);
Node* pre = nullptr;
while(q.size()) {
int sz = q.size();
for(int i = 0; i < sz; ++i) {
Node* node = q.front();
q.pop();
if(node->left) {
q.push(node->left);
q.push(node->right);
}
if(!pre) {
pre = node;
} else {
pre->next = node;
pre = node;
}
}
pre = nullptr;
}
return root;
}
};
|
Accepted
58/58 cases passed (40 ms)
Your runtime beats 27.01 % of cpp submissions
Your memory usage beats 39.05 % of cpp submissions (19.6 MB)
递归
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| class Solution {
public:
Node* connect(Node* root) {
if(!root)
return root;
helper(root->left, root->right);
return root;
}
void helper(Node* left, Node* right) {
if(!left || !right)
return ;
left->next = right;
helper(left->left, left->right);
helper(left->right, right->left);
helper(right->left, right->right);
}
};
|
Accepted
58/58 cases passed (36 ms)
Your runtime beats 32.24 % of cpp submissions
Your memory usage beats 63.08 % of cpp submissions (19.3 MB)
