class Solution { public: vector<vector<int>> levelOrder(TreeNode* root) { vector <vector <int>> ret; if (!root) { return ret; } queue <TreeNode*> q; q.push(root); while (!q.empty()) { int currentLevelSize = q.size(); ret.push_back(vector <int> ()); for (int i = 1; i <= currentLevelSize; ++i) { auto node = q.front(); q.pop(); ret.back().push_back(node->val); if (node->left) q.push(node->left); if (node->right) q.push(node->right); } } return ret; } };
void recurseion(struct TreeNode* root, int* returnSize, int* col, int cnt,int** arr){ if (!root) return; if (cnt+1 > *returnSize) *returnSize = cnt+1; if (col[cnt] == 0) arr[cnt] = (int*)calloc(1000, sizeof(int*)); arr[cnt][col[cnt]++] = root->val; recurseion(root->left, returnSize, col, cnt+1, arr); recurseion(root->right, returnSize, col, cnt+1, arr); } int** levelOrder(struct TreeNode* root, int* returnSize, int** returnColumnSizes){ int** arr = (int**)calloc(1000, sizeof(int*)); *returnSize = 0; *returnColumnSizes = (int*)calloc(1000, sizeof(int)); recurseion(root, returnSize, *returnColumnSizes, 0, arr); return arr; }