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feat: add python and java solutions to leetcode problem: No.0213
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‎README.md

+3
Original file line numberDiff line numberDiff line change
@@ -83,6 +83,9 @@
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### 动态规划
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86+
1. [打家劫舍](/solution/0100-0199/0198.House%20Robber/README.md)
87+
1. [打家劫舍 II](/solution/0200-0299/0213.House%20Robber%20II/README.md)
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8689
### 混合问题
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## 维护者

‎README_EN.md

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Original file line numberDiff line numberDiff line change
@@ -78,6 +78,9 @@ Complete solutions to [LeetCode](https://leetcode-cn.com/problemset/all/), [LCOF
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### Dynamic Programming
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1. [House Robber](/solution/0100-0199/0198.House%20Robber/README_EN.md)
82+
1. [House Robber II](/solution/0200-0299/0213.House%20Robber%20II/README_EN.md)
83+
8184
### Misc
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## Maintainer

‎solution/0100-0199/0198.House Robber/README.md

+10-10
Original file line numberDiff line numberDiff line change
@@ -42,12 +42,11 @@ class Solution:
4242
n = len(nums)
4343
if n == 1:
4444
return nums[0]
45-
dp = [0 for _ in range(n)]
46-
dp[0] = nums[0]
47-
dp[1] = max(nums[0], nums[1])
45+
pre, cur = nums[0], max(nums[0], nums[1])
4846
for i in range(2, n):
49-
dp[i] = max(dp[i - 1], dp[i - 2] + nums[i])
50-
return dp[n - 1]
47+
t = max(pre + nums[i], cur)
48+
pre, cur = cur, t
49+
return cur
5150
```
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### **Java**
@@ -64,13 +63,14 @@ class Solution {
6463
if (n == 1) {
6564
return nums[0];
6665
}
67-
int[] dp = new int[n];
68-
dp[0] = nums[0];
69-
dp[1] = Math.max(nums[0], nums[1]);
66+
int pre = nums[0];
67+
int cur = Math.max(nums[0], nums[1]);
7068
for (int i = 2; i < n; ++i) {
71-
dp[i] = Math.max(dp[i - 1], dp[i - 2] + nums[i]);
69+
int t = Math.max(pre + nums[i], cur);
70+
pre = cur;
71+
cur = t;
7272
}
73-
return dp[n - 1];
73+
return cur;
7474
}
7575
}
7676
```

‎solution/0100-0199/0198.House Robber/README_EN.md

+10-10
Original file line numberDiff line numberDiff line change
@@ -48,12 +48,11 @@ class Solution:
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n = len(nums)
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if n == 1:
5050
return nums[0]
51-
dp = [0 for _ in range(n)]
52-
dp[0] = nums[0]
53-
dp[1] = max(nums[0], nums[1])
51+
pre, cur = nums[0], max(nums[0], nums[1])
5452
for i in range(2, n):
55-
dp[i] = max(dp[i - 1], dp[i - 2] + nums[i])
56-
return dp[n - 1]
53+
t = max(pre + nums[i], cur)
54+
pre, cur = cur, t
55+
return cur
5756
```
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### **Java**
@@ -68,13 +67,14 @@ class Solution {
6867
if (n == 1) {
6968
return nums[0];
7069
}
71-
int[] dp = new int[n];
72-
dp[0] = nums[0];
73-
dp[1] = Math.max(nums[0], nums[1]);
70+
int pre = nums[0];
71+
int cur = Math.max(nums[0], nums[1]);
7472
for (int i = 2; i < n; ++i) {
75-
dp[i] = Math.max(dp[i - 1], dp[i - 2] + nums[i]);
73+
int t = Math.max(pre + nums[i], cur);
74+
pre = cur;
75+
cur = t;
7676
}
77-
return dp[n - 1];
77+
return cur;
7878
}
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}
8080
```

‎solution/0100-0199/0198.House Robber/Solution.java

+6-5
Original file line numberDiff line numberDiff line change
@@ -7,12 +7,13 @@ public int rob(int[] nums) {
77
if (n == 1) {
88
return nums[0];
99
}
10-
int[] dp = new int[n];
11-
dp[0] = nums[0];
12-
dp[1] = Math.max(nums[0], nums[1]);
10+
int pre = nums[0];
11+
int cur = Math.max(nums[0], nums[1]);
1312
for (int i = 2; i < n; ++i) {
14-
dp[i] = Math.max(dp[i - 1], dp[i - 2] + nums[i]);
13+
int t = Math.max(pre + nums[i], cur);
14+
pre = cur;
15+
cur = t;
1516
}
16-
return dp[n - 1];
17+
return cur;
1718
}
1819
}

‎solution/0100-0199/0198.House Robber/Solution.py

+4-5
Original file line numberDiff line numberDiff line change
@@ -5,9 +5,8 @@ def rob(self, nums: List[int]) -> int:
55
n = len(nums)
66
if n == 1:
77
return nums[0]
8-
dp = [0 for _ in range(n)]
9-
dp[0] = nums[0]
10-
dp[1] = max(nums[0], nums[1])
8+
pre, cur = nums[0], max(nums[0], nums[1])
119
for i in range(2, n):
12-
dp[i] = max(dp[i - 1], dp[i - 2] + nums[i])
13-
return dp[n - 1]
10+
t = max(pre + nums[i], cur)
11+
pre, cur = cur, t
12+
return cur

‎solution/0200-0299/0213.House Robber II/README.md

+54-2
Original file line numberDiff line numberDiff line change
@@ -27,22 +27,74 @@
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2828
<!-- 这里可写通用的实现逻辑 -->
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30+
环状排列意味着第一个房屋和最后一个房屋中最多只能选择一个偷窃，因此可以把此环状排列房间问题约化为两个单排排列房屋子问题。
31+
32+
- 不偷第一个房屋（那么最后一个房屋能偷），即求：`_rob(nums[1:])`
33+
- 偷第一个房屋（那么最后一个房屋不能偷），即求：`_rob(nums[:-1])`
34+
35+
即 `res = max(_rob(nums[1:]), _rob(nums[:-1]))`
36+
3037
<!-- tabs:start -->
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3239
### **Python3**
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3441
<!-- 这里可写当前语言的特殊实现逻辑 -->
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3643
```python
37-
44+
class Solution:
45+
def rob(self, nums: List[int]) -> int:
46+
def _rob(nums):
47+
n = len(nums)
48+
if n == 0:
49+
return 0
50+
if n == 1:
51+
return nums[0]
52+
pre, cur = nums[0], max(nums[0], nums[1])
53+
for i in range(2, n):
54+
t = max(pre + nums[i], cur)
55+
pre, cur = cur, t
56+
return cur
57+
58+
n = len(nums)
59+
if n == 1:
60+
return nums[0]
61+
return max(_rob(nums[1:]), _rob(nums[:-1]))
3862
```
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4064
### **Java**
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4266
<!-- 这里可写当前语言的特殊实现逻辑 -->
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4468
```java
45-
69+
class Solution {
70+
public int rob(int[] nums) {
71+
int n = nums.length;
72+
if (n == 1) {
73+
return nums[0];
74+
}
75+
int sub1 = robInternal(Arrays.copyOfRange(nums, 0, n - 1));
76+
int sub2 = robInternal(Arrays.copyOfRange(nums, 1, n));
77+
return Math.max(sub1, sub2);
78+
}
79+
80+
private int robInternal(int[] nums) {
81+
int n;
82+
if ((n = nums.length) == 0) {
83+
return 0;
84+
}
85+
if (n == 1) {
86+
return nums[0];
87+
}
88+
int pre = nums[0];
89+
int cur = Math.max(nums[0], nums[1]);
90+
for (int i = 2; i < n; ++i) {
91+
int t = Math.max(pre + nums[i], cur);
92+
pre = cur;
93+
cur = t;
94+
}
95+
return cur;
96+
}
97+
}
4698
```
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48100
### **...**

‎solution/0200-0299/0213.House Robber II/README_EN.md

+47-2
Original file line numberDiff line numberDiff line change
@@ -41,13 +41,58 @@
4141
### **Python3**
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4343
```python
44-
44+
class Solution:
45+
def rob(self, nums: List[int]) -> int:
46+
def _rob(nums):
47+
n = len(nums)
48+
if n == 0:
49+
return 0
50+
if n == 1:
51+
return nums[0]
52+
pre, cur = nums[0], max(nums[0], nums[1])
53+
for i in range(2, n):
54+
t = max(pre + nums[i], cur)
55+
pre, cur = cur, t
56+
return cur
57+
58+
n = len(nums)
59+
if n == 1:
60+
return nums[0]
61+
return max(_rob(nums[1:]), _rob(nums[:-1]))
4562
```
4663

4764
### **Java**
4865

4966
```java
50-
67+
class Solution {
68+
public int rob(int[] nums) {
69+
int n = nums.length;
70+
if (n == 1) {
71+
return nums[0];
72+
}
73+
int sub1 = robInternal(Arrays.copyOfRange(nums, 0, n - 1));
74+
int sub2 = robInternal(Arrays.copyOfRange(nums, 1, n));
75+
return Math.max(sub1, sub2);
76+
}
77+
78+
private int robInternal(int[] nums) {
79+
int n;
80+
if ((n = nums.length) == 0) {
81+
return 0;
82+
}
83+
if (n == 1) {
84+
return nums[0];
85+
}
86+
int pre = nums[0];
87+
int cur = Math.max(nums[0], nums[1]);
88+
for (int i = 2; i < n; ++i) {
89+
int t = Math.max(pre + nums[i], cur);
90+
pre = cur;
91+
cur = t;
92+
}
93+
return cur;
94+
}
95+
}
5196
```
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5398
### **...**

‎solution/0200-0299/0213.House Robber II/Solution.java

+28-40
Original file line numberDiff line numberDiff line change
@@ -1,41 +1,29 @@
1-
public class Solution {
2-
public static int rob(int[] nums) {
3-
4-
if (nums == null || nums.length == 0) {
5-
return 0;
6-
}
7-
8-
if (nums.length == 1) {
9-
return nums[0];
10-
}
11-
12-
if (nums.length == 2) {
13-
return Math.max(nums[0], nums[1]);
14-
}
15-
16-
return Math.max(help(Arrays.copyOfRange(nums, 0, nums.length - 1)),
17-
help(Arrays.copyOfRange(nums, 1, nums.length)));
18-
}
19-
20-
public static int help(int[] nums) {
21-
22-
if (nums.length == 0) {
23-
return 0;
24-
}
25-
26-
if (nums.length == 1) {
27-
return nums[0];
28-
}
29-
30-
int[] P = new int[nums.length];
31-
32-
P[0] = nums[0];
33-
P[1] = Math.max(nums[0], nums[1]);
34-
35-
for (int i = 2; i < nums.length; i++) {
36-
P[i] = Math.max(nums[i] + P[i - 2], P[i - 1]);
37-
}
38-
39-
return P[nums.length - 1];
40-
}
1+
class Solution {
2+
public int rob(int[] nums) {
3+
int n = nums.length;
4+
if (n == 1) {
5+
return nums[0];
6+
}
7+
int sub1 = robInternal(Arrays.copyOfRange(nums, 0, n - 1));
8+
int sub2 = robInternal(Arrays.copyOfRange(nums, 1, n));
9+
return Math.max(sub1, sub2);
10+
}
11+
12+
private int robInternal(int[] nums) {
13+
int n;
14+
if ((n = nums.length) == 0) {
15+
return 0;
16+
}
17+
if (n == 1) {
18+
return nums[0];
19+
}
20+
int pre = nums[0];
21+
int cur = Math.max(nums[0], nums[1]);
22+
for (int i = 2; i < n; ++i) {
23+
int t = Math.max(pre + nums[i], cur);
24+
pre = cur;
25+
cur = t;
26+
}
27+
return cur;
28+
}
4129
}

‎solution/0200-0299/0213.House Robber II/Solution.py

+18
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,18 @@
1+
class Solution:
2+
def rob(self, nums: List[int]) -> int:
3+
def _rob(nums):
4+
n = len(nums)
5+
if n == 0:
6+
return 0
7+
if n == 1:
8+
return nums[0]
9+
pre, cur = nums[0], max(nums[0], nums[1])
10+
for i in range(2, n):
11+
t = max(pre + nums[i], cur)
12+
pre, cur = cur, t
13+
return cur
14+
15+
n = len(nums)
16+
if n == 1:
17+
return nums[0]
18+
return max(_rob(nums[1:]), _rob(nums[:-1]))

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