LeetCode 198.打家劫舍

题目链接：

LeetCode 198.打家劫舍

代码：

class Solution {
public:
    int rob(vector<int>& nums) {
        int size = nums.size();
        if (nums.size() == 0) return 0;
        if(size == 1) return nums[0];
        vector<int>dp(size,0);
        dp[0] = nums[0];
        dp[1] = max(nums[1],nums[0]);
        for(int i=2;i<size;i++){
            dp[i] = max(dp[i-1],dp[i-2]+nums[i]);
        }
        return dp[size-1];
    }
};

LeetCode 213.打家劫舍Ⅱ

题目链接：

LeetCode 213.打家劫舍Ⅱ

代码：

class Solution {
public:
    int rob(vector<int>& nums) {
        vector<int>dp(nums.size()-1,0);
        vector<int>dp1(nums.size()-1,0);
        if(nums.size()==0 ) return 0;
        if(nums.size()==1) return nums[0];
        if(nums.size()==2) return max(nums[0],nums[1]);
        dp[0] = nums[0];
        dp[1] = max(nums[0],nums[1]);
        dp1[0] = nums[1];
        dp1[1] = max(nums[1],nums[2]);
        for(int i=2;i<nums.size()-1;i++){
            dp[i] = max(dp[i-1],dp[i-2]+nums[i]);
            dp1[i]=max(dp1[i-1],dp1[i-2]+nums[i+1]);
        }
        return max(dp[nums.size()-2],dp1[nums.size()-2]);
    }
};

LeetCode 337.打家劫舍Ⅲ

题目链接：

LeetCode 337.打家劫舍Ⅲ

代码：

class Solution {
public:
    int rob(TreeNode* root) {
        vector<int>result = robTree(root);
        return max(result[0],result[1]);
    }
    vector<int>robTree(TreeNode*cur){
        //0不偷 1偷
        if(cur==nullptr) return {0,0};
        vector<int>left = robTree(cur->left);
        vector<int>right = robTree(cur->right);
        //偷
        int val1 = cur->val + right[0] + left[0];
        //不偷
        int val2 = max(left[0],left[1]) + max(right[0],right[1]);
        return{val2, val1};
    }
};