题解 | #从上往下打印二叉树#
从上往下打印二叉树
https://www.nowcoder.com/practice/7fe2212963db4790b57431d9ed259701
gap把我看糊涂了，写个简单的
#define MAX_SIZE 10001
int* levelOrder(struct TreeNode* root, int* returnSize){
*returnSize = 0;
if (root == NULL) {
return NULL;
}
int *ans = (int*)calloc(MAX_SIZE, sizeof(int));
struct TreeNode *queue[MAX_SIZE];//指针数组，存放一组指针
memset(queue, 0, sizeof(struct TreeNode*));
int head = 0;
int tail = 0;
queue[tail++] = root;
while (head < tail) {
struct TreeNode *tmp = queue[head++];
ans[(*returnSize)++] = tmp->val;
if (tmp->left != NULL) {
queue[tail++] = tmp->left;
}
if (tmp->right != NULL) {
queue[tail++] = tmp->right;
}
}
return ans;
}
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