169 229 669 【未完成】

class Solution {
public:
    int majorityElement(vector<int>& nums) {
        QuickSort(vector<int>& nums,0,right);
        int count=0;
        for(int i=0;i<nums.size();i++){
            if(i>=1&&nums[i]!=nums[i-1]){
                count=1;
            }else{
                count++;
            }
            if(count>=nums.size()/2) return nums[i];
        }
    }
    void QuickSort(vector<int>& nums,int left,int right){
        if(left>=right)return;
        int index=QuickSort(nums,left,right);
        QuickSort(nums,left,index-1);
        QuickSort(nums,index+1,right);
        
    }
    int PartSort(vector<int>& nums,int left,int right){
        int key=right;
        while(left<right){
            while(left<right && nums[left]<=nums[key]){
                left++;
            }
            while(left<right && nums[right]>=nums[key]){
                right++;
            }
            swap(nums[left],nums[right]);
        }
        swap(nums[left],nums[key]);
        return left;
    }
};

python   摩尔投票

class Solution(object):
    def majorityElement(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        dict={}
        for num in nums:
            if num not in dict:
                dict[num]=1
            else:
                dict[num]++
            if dict[num]>len(nums)/2:
                return num

229

笨办法，，，明天好好和大佬讨论下

class Solution(object):
    def majorityElement(self, nums):
        """
        :type nums: List[int]
        :rtype: List[int]
        """
        List=[]
        dict={}
        candidate=None
        count=0
        for num in nums:
            if num not in dict:
                dict[num]=1
            else:
                dict[num]+=1
            if dict[num]>len(nums)/3 and num not in List:
                List.append(num)
        return List

669

错误代码：太天真

/**
 * 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:
    TreeNode* trimBST(TreeNode* root, int L, int R) {
        if(root==NULL) return root;
        while(root->val!=L){
            if(L>root->val) root=root->right;
            if(L<root->val) root=root->left;
        }
        TreeNode* temp=root;
        while(temp->val!=R){
            if(R>temp->val){
                temp->left=NULL;
                temp=temp->right;
            }else{
                temp->right=NULL;
                temp=temp->left;
            }
        }
        return root;
    }
};

使用正确的遍历方法：

# Definition for a binary tree node.
# class TreeNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Solution(object):
    def trimBST(self, root, L, R):
        """
        :type root: TreeNode
        :type L: int
        :type R: int
        :rtype: TreeNode
        """
        if root is None:
            return None
        if root.val<L:
            return self.trimBST(root.right,L,R)
        if root.val>R:
            return self.trimBST(root.left,L,R)
        root.left=self.trimBST(root.left,L,R)
        root.right=self.trimBST(root.right,L,R)
        return root

背过别人的代码，明天再看