LeetCode题目记录-654. 最大二叉树(C++代码实现)

C++代码实现：

class Solution {
public:

    //digui
    TreeNode* digui(vector& nums,int begin,int end){
        if(begin > end){
            return nullptr;
        }

        //得到当前范围内的最大值索引
        int maxIndex = getCurrIndex(nums,begin,end);
        //构造根节点
        TreeNode* root = new TreeNode(nums[maxIndex]);

        root->left = digui(nums,begin,maxIndex - 1);
        root->right = digui(nums,maxIndex + 1,end);

        return root;
    }

    //得到最大索引值的方法
    int getCurrIndex(vector& nums,int begin,int end){

        int maxIndex = INT_MIN;
        int maxNum = INT_MIN;

        for(int i = begin;i <= end;i++){
            if(nums[i] > maxNum){
                maxIndex = i;
                maxNum = nums[i];
            }
        }

        return maxIndex;
    }


    TreeNode* constructMaximumBinaryTree(vector& nums) {
        int n = nums.size();
        TreeNode* root = digui(nums,0,n - 1);

        return root;
    }
};