654. Maximum Binary Tree
2020-04-07 本文已影响0人
是嘤嘤嘤呀
image.png
思路:正常遍历生成树结构即可
代码:
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
int getMaximumIndex(vector<int>& nums, int left, int right) {
int index = left;
for (int i = left; i <= right; i++) {
if (nums[index] < nums[i]) index = i;
}
return index;
}
TreeNode* solution(vector<int>& nums, int i, int j) {
if (i > j) return NULL;
int index = getMaximumIndex(nums, i, j);
TreeNode* root = new TreeNode(nums[index]);
root -> left = solution(nums, i, index - 1);
root -> right = solution(nums, index + 1, j);
return root;
}
TreeNode* constructMaximumBinaryTree(vector<int>& nums) {
return solution(nums, 0, nums.size() - 1);
}
};