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feat: add solutions to lc problem: No.0565
No.0565.Array Nesting
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‎solution/0500-0599/0565.Array Nesting/README.md

+88-1
Original file line numberDiff line numberDiff line change
@@ -37,7 +37,17 @@ S[0] = {A[0], A[5], A[6], A[2]} = {5, 6, 2, 0}
3737

3838
<!-- 这里可写通用的实现逻辑 -->
3939

40-
嵌套数组最终一定会形成一个环，在枚举 `S[i]` 的过程中，可以用 `vis` 数组剪枝，避免重复枚举同一个环
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**方法一：图**
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42+
嵌套数组最终一定会形成一个环，在枚举 $nums[i]$ 的过程中，可以用 $vis$ 数组剪枝，避免重复枚举同一个环。
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时间复杂度 $O(n)$，空间复杂度 $O(n)$。
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**方法二：原地标记**
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48+
由于 $nums$ 元素均在 $[0..n-1]$ 之间，因此，对于访问过的元素，我们可以令 $nums[i]=n$，从而省略 $vis$ 数组。
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时间复杂度 $O(n)$，空间复杂度 $O(1)$。
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4252
<!-- tabs:start -->
4353

@@ -64,6 +74,21 @@ class Solution:
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return res
6575
```
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```python
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class Solution:
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def arrayNesting(self, nums: List[int]) -> int:
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ans, n = 0, len(nums)
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for i in range(n):
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cnt = 0
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while nums[i] != n:
84+
j = nums[i]
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nums[i] = n
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i = j
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cnt += 1
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ans = max(ans, cnt)
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return ans
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```
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6792
### **Java**
6893

6994
<!-- 这里可写当前语言的特殊实现逻辑 -->
@@ -92,6 +117,26 @@ class Solution {
92117
}
93118
```
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120+
```java
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class Solution {
122+
public int arrayNesting(int[] nums) {
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int ans = 0, n = nums.length;
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for (int i = 0; i < n; ++i) {
125+
int cnt = 0;
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int j = i;
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while (nums[j] < n) {
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int k = nums[j];
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nums[j] = n;
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j = k;
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++cnt;
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}
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ans = Math.max(ans, cnt);
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}
135+
return ans;
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}
137+
}
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```
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95140
### **C++**
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97142
```cpp
@@ -117,6 +162,29 @@ public:
117162
};
118163
```
119164
165+
```cpp
166+
class Solution {
167+
public:
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int arrayNesting(vector<int>& nums) {
169+
int ans = 0, n = nums.size();
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for (int i = 0; i < n; ++i)
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{
172+
int cnt = 0;
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int j = i;
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while (nums[j] < n)
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{
176+
int k = nums[j];
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nums[j] = n;
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j = k;
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++cnt;
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}
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ans = max(ans, cnt);
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}
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return ans;
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}
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};
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```
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120188
### **Go**
121189

122190
```go
@@ -143,6 +211,25 @@ func arrayNesting(nums []int) int {
143211
}
144212
```
145213

214+
```go
215+
func arrayNesting(nums []int) int {
216+
ans, n := 0, len(nums)
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for i := range nums {
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cnt, j := 0, i
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for nums[j] != n {
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k := nums[j]
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nums[j] = n
222+
j = k
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cnt++
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}
225+
if ans < cnt {
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ans = cnt
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}
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}
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return ans
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}
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```
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146233
### **...**
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148235
```

‎solution/0500-0599/0565.Array Nesting/README_EN.md

+77
Original file line numberDiff line numberDiff line change
@@ -69,6 +69,21 @@ class Solution:
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return res
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```
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```python
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class Solution:
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def arrayNesting(self, nums: List[int]) -> int:
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ans, n = 0, len(nums)
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for i in range(n):
77+
cnt = 0
78+
while nums[i] != n:
79+
j = nums[i]
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nums[i] = n
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i = j
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cnt += 1
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ans = max(ans, cnt)
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return ans
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```
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7287
### **Java**
7388

7489
```java
@@ -95,6 +110,26 @@ class Solution {
95110
}
96111
```
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113+
```java
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class Solution {
115+
public int arrayNesting(int[] nums) {
116+
int ans = 0, n = nums.length;
117+
for (int i = 0; i < n; ++i) {
118+
int cnt = 0;
119+
int j = i;
120+
while (nums[j] < n) {
121+
int k = nums[j];
122+
nums[j] = n;
123+
j = k;
124+
++cnt;
125+
}
126+
ans = Math.max(ans, cnt);
127+
}
128+
return ans;
129+
}
130+
}
131+
```
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98133
### **C++**
99134

100135
```cpp
@@ -120,6 +155,29 @@ public:
120155
};
121156
```
122157
158+
```cpp
159+
class Solution {
160+
public:
161+
int arrayNesting(vector<int>& nums) {
162+
int ans = 0, n = nums.size();
163+
for (int i = 0; i < n; ++i)
164+
{
165+
int cnt = 0;
166+
int j = i;
167+
while (nums[j] < n)
168+
{
169+
int k = nums[j];
170+
nums[j] = n;
171+
j = k;
172+
++cnt;
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}
174+
ans = max(ans, cnt);
175+
}
176+
return ans;
177+
}
178+
};
179+
```
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123181
### **Go**
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125183
```go
@@ -146,6 +204,25 @@ func arrayNesting(nums []int) int {
146204
}
147205
```
148206

207+
```go
208+
func arrayNesting(nums []int) int {
209+
ans, n := 0, len(nums)
210+
for i := range nums {
211+
cnt, j := 0, i
212+
for nums[j] != n {
213+
k := nums[j]
214+
nums[j] = n
215+
j = k
216+
cnt++
217+
}
218+
if ans < cnt {
219+
ans = cnt
220+
}
221+
}
222+
return ans
223+
}
224+
```
225+
149226
### **...**
150227

151228
```

‎solution/0500-0599/0565.Array Nesting/Solution.cpp

+14-14
Original file line numberDiff line numberDiff line change
@@ -1,20 +1,20 @@
11
class Solution {
22
public:
33
int arrayNesting(vector<int>& nums) {
4-
int n = nums.size();
5-
vector<bool> vis(n);
6-
int res = 0;
7-
for (int i = 0; i < n; ++i) {
8-
if (vis[i]) continue;
9-
int cur = nums[i], m = 1;
10-
vis[cur] = true;
11-
while (nums[cur] != nums[i]) {
12-
cur = nums[cur];
13-
++m;
14-
vis[cur] = true;
4+
int ans = 0, n = nums.size();
5+
for (int i = 0; i < n; ++i)
6+
{
7+
int cnt = 0;
8+
int j = i;
9+
while (nums[j] < n)
10+
{
11+
int k = nums[j];
12+
nums[j] = n;
13+
j = k;
14+
++cnt;
1515
}
16-
res = max(res, m);
16+
ans = max(ans, cnt);
1717
}
18-
return res;
18+
return ans;
1919
}
20-
};
20+
};

‎solution/0500-0599/0565.Array Nesting/Solution.go

+11-16
Original file line numberDiff line numberDiff line change
@@ -1,21 +1,16 @@
11
func arrayNesting(nums []int) int {
2-
n := len(nums)
3-
vis := make([]bool, n)
4-
ans := 0
5-
for i := 0; i < n; i++ {
6-
if vis[i] {
7-
continue
2+
ans, n := 0, len(nums)
3+
for i := range nums {
4+
cnt, j := 0, i
5+
for nums[j] != n {
6+
k := nums[j]
7+
nums[j] = n
8+
j = k
9+
cnt++
810
}
9-
cur, m := nums[i], 1
10-
vis[cur] = true
11-
for nums[cur] != nums[i] {
12-
cur = nums[cur]
13-
m++
14-
vis[cur] = true
15-
}
16-
if m > ans {
17-
ans = m
11+
if ans < cnt {
12+
ans = cnt
1813
}
1914
}
2015
return ans
21-
}
16+
}

‎solution/0500-0599/0565.Array Nesting/Solution.java

+11-15
Original file line numberDiff line numberDiff line change
@@ -1,21 +1,17 @@
11
class Solution {
22
public int arrayNesting(int[] nums) {
3-
int n = nums.length;
4-
boolean[] vis = new boolean[n];
5-
int res = 0;
6-
for (int i = 0; i < n; i++) {
7-
if (vis[i]) {
8-
continue;
3+
int ans = 0, n = nums.length;
4+
for (int i = 0; i < n; ++i) {
5+
int cnt = 0;
6+
int j = i;
7+
while (nums[j] < n) {
8+
int k = nums[j];
9+
nums[j] = n;
10+
j = k;
11+
++cnt;
912
}
10-
int cur = nums[i], m = 1;
11-
vis[cur] = true;
12-
while (nums[cur] != nums[i]) {
13-
cur = nums[cur];
14-
m++;
15-
vis[cur] = true;
16-
}
17-
res = Math.max(res, m);
13+
ans = Math.max(ans, cnt);
1814
}
19-
return res;
15+
return ans;
2016
}
2117
}

‎solution/0500-0599/0565.Array Nesting/Solution.py

+9-13
Original file line numberDiff line numberDiff line change
@@ -1,16 +1,12 @@
11
class Solution:
22
def arrayNesting(self, nums: List[int]) -> int:
3-
n = len(nums)
4-
vis = [False] * n
5-
res = 0
3+
ans, n = 0, len(nums)
64
for i in range(n):
7-
if vis[i]:
8-
continue
9-
cur, m = nums[i], 1
10-
vis[cur] = True
11-
while nums[cur] != nums[i]:
12-
cur = nums[cur]
13-
m += 1
14-
vis[cur] = True
15-
res = max(res, m)
16-
return res
5+
cnt = 0
6+
while nums[i] != n:
7+
j = nums[i]
8+
nums[i] = n
9+
i = j
10+
cnt += 1
11+
ans = max(ans, cnt)
12+
return ans

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