diff --git a/.prettierignore b/.prettierignore
index 13715bc116db8..47b55e9bdf606 100644
--- a/.prettierignore
+++ b/.prettierignore
@@ -26,3 +26,4 @@ node_modules/
/solution/3100-3199/3150.Invalid Tweets II/Solution.sql
/solution/3100-3199/3198.Find Cities in Each State/Solution.sql
/solution/3300-3399/3328.Find Cities in Each State II/Solution.sql
+/solution/3400-3499/3451.Find Invalid IP Addresses/Solution.sql
diff --git a/solution/0000-0099/0027.Remove Element/README.md b/solution/0000-0099/0027.Remove Element/README.md
index 66512c052c070..e0a104c1eb0d9 100644
--- a/solution/0000-0099/0027.Remove Element/README.md
+++ b/solution/0000-0099/0027.Remove Element/README.md
@@ -205,6 +205,22 @@ var removeElement = function (nums, val) {
};
```
+#### C#
+
+```cs
+public class Solution {
+ public int RemoveElement(int[] nums, int val) {
+ int k = 0;
+ foreach (int x in nums) {
+ if (x != val) {
+ nums[k++] = x;
+ }
+ }
+ return k;
+ }
+}
+```
+
#### PHP
```php
diff --git a/solution/0000-0099/0027.Remove Element/README_EN.md b/solution/0000-0099/0027.Remove Element/README_EN.md
index e033fd507fbbd..6bbc22e167933 100644
--- a/solution/0000-0099/0027.Remove Element/README_EN.md
+++ b/solution/0000-0099/0027.Remove Element/README_EN.md
@@ -205,6 +205,22 @@ var removeElement = function (nums, val) {
};
```
+#### C#
+
+```cs
+public class Solution {
+ public int RemoveElement(int[] nums, int val) {
+ int k = 0;
+ foreach (int x in nums) {
+ if (x != val) {
+ nums[k++] = x;
+ }
+ }
+ return k;
+ }
+}
+```
+
#### PHP
```php
diff --git a/solution/0000-0099/0027.Remove Element/Solution.cs b/solution/0000-0099/0027.Remove Element/Solution.cs
new file mode 100644
index 0000000000000..1ded258b8a3eb
--- /dev/null
+++ b/solution/0000-0099/0027.Remove Element/Solution.cs
@@ -0,0 +1,11 @@
+public class Solution {
+ public int RemoveElement(int[] nums, int val) {
+ int k = 0;
+ foreach (int x in nums) {
+ if (x != val) {
+ nums[k++] = x;
+ }
+ }
+ return k;
+ }
+}
\ No newline at end of file
diff --git a/solution/1700-1799/1742.Maximum Number of Balls in a Box/README.md b/solution/1700-1799/1742.Maximum Number of Balls in a Box/README.md
index 201650a5221bf..fdbf53dd7d59c 100644
--- a/solution/1700-1799/1742.Maximum Number of Balls in a Box/README.md
+++ b/solution/1700-1799/1742.Maximum Number of Balls in a Box/README.md
@@ -76,11 +76,11 @@ tags:
### 方法一：数组 + 模拟
-观察题目的数据范围，小球的编号最大不超过 $10^5$，那么每个编号的各个位数之和的最大值小于 $50$。因此，我们可以直接开一个长度为 $50$ 的数组 $cnt$ 来统计每个编号的各个位数之和的数量。
+观察题目的数据范围，小球的编号最大不超过 $10^5$，那么每个编号的各个位数之和的最大值小于 $50$。因此，我们可以直接开一个长度为 $50$ 的数组 $\textit{cnt}$ 来统计每个编号的各个位数之和的数量。
-答案就是数组 $cnt$ 中的最大值。
+答案就是数组 $\textit{cnt}$ 中的最大值。
-时间复杂度 $O(n \times \log_{10}m)$。其中 $n = highLimit - lowLimit + 1$，而 $m = highLimit$。
+时间复杂度 $O(n \times \log_{10}m)$。其中 $n = \textit{highLimit} - \textit{lowLimit} + 1$，而 $m = \textit{highLimit}$。
@@ -172,6 +172,67 @@ function countBalls(lowLimit: number, highLimit: number): number {
}
```
+#### Rust
+
+```rust
+impl Solution {
+ pub fn count_balls(low_limit: i32, high_limit: i32) -> i32 {
+ let mut cnt = vec![0; 50];
+ for x in low_limit..=high_limit {
+ let mut y = 0;
+ let mut n = x;
+ while n > 0 {
+ y += n % 10;
+ n /= 10;
+ }
+ cnt[y as usize] += 1;
+ }
+ *cnt.iter().max().unwrap()
+ }
+}
+```
+
+#### JavaScript
+
+```js
+/**
+ * @param {number} lowLimit
+ * @param {number} highLimit
+ * @return {number}
+ */
+var countBalls = function (lowLimit, highLimit) {
+ const cnt = Array(50).fill(0);
+ for (let i = lowLimit; i <= highLimit; ++i) {
+ let y = 0;
+ for (let x = i; x; x = Math.floor(x / 10)) {
+ y += x % 10;
+ }
+ ++cnt[y];
+ }
+ return Math.max(...cnt);
+};
+```
+
+#### C#
+
+```cs
+public class Solution {
+ public int CountBalls(int lowLimit, int highLimit) {
+ int[] cnt = new int[50];
+ for (int x = lowLimit; x <= highLimit; x++) {
+ int y = 0;
+ int n = x;
+ while (n > 0) {
+ y += n % 10;
+ n /= 10;
+ }
+ cnt[y]++;
+ }
+ return cnt.Max();
+ }
+}
+```
+
diff --git a/solution/1700-1799/1742.Maximum Number of Balls in a Box/README_EN.md b/solution/1700-1799/1742.Maximum Number of Balls in a Box/README_EN.md
index f76f6e7f9877a..519ee846cc15e 100644
--- a/solution/1700-1799/1742.Maximum Number of Balls in a Box/README_EN.md
+++ b/solution/1700-1799/1742.Maximum Number of Balls in a Box/README_EN.md
@@ -74,11 +74,11 @@ Box 10 has the most number of balls with 2 balls.
### Solution 1: Array + Simulation
-Observing the data range of the problem, the maximum number of the ball does not exceed $10^5$, so the maximum value of the sum of each digit of the number is less than $50$. Therefore, we can directly create an array $cnt$ with a length of $50$ to count the number of each digit sum of each number.
+Observing the problem's data range, the maximum number of balls does not exceed $10^5$, so the maximum sum of the digits of each number is less than $50$. Therefore, we can directly create an array $\textit{cnt}$ of length $50$ to count the number of occurrences of each digit sum.
-The answer is the maximum value in the array $cnt$.
+The answer is the maximum value in the array $\textit{cnt}$.
-The time complexity is $O(n \times \log_{10}m)$. Here, $n = highLimit - lowLimit + 1$, and $m = highLimit$.
+The time complexity is $O(n \times \log_{10}m)$. Here, $n = \textit{highLimit} - \textit{lowLimit} + 1$, and $m = \textit{highLimit}$.
@@ -170,6 +170,67 @@ function countBalls(lowLimit: number, highLimit: number): number {
}
```
+#### Rust
+
+```rust
+impl Solution {
+ pub fn count_balls(low_limit: i32, high_limit: i32) -> i32 {
+ let mut cnt = vec![0; 50];
+ for x in low_limit..=high_limit {
+ let mut y = 0;
+ let mut n = x;
+ while n > 0 {
+ y += n % 10;
+ n /= 10;
+ }
+ cnt[y as usize] += 1;
+ }
+ *cnt.iter().max().unwrap()
+ }
+}
+```
+
+#### JavaScript
+
+```js
+/**
+ * @param {number} lowLimit
+ * @param {number} highLimit
+ * @return {number}
+ */
+var countBalls = function (lowLimit, highLimit) {
+ const cnt = Array(50).fill(0);
+ for (let i = lowLimit; i <= highLimit; ++i) {
+ let y = 0;
+ for (let x = i; x; x = Math.floor(x / 10)) {
+ y += x % 10;
+ }
+ ++cnt[y];
+ }
+ return Math.max(...cnt);
+};
+```
+
+#### C#
+
+```cs
+public class Solution {
+ public int CountBalls(int lowLimit, int highLimit) {
+ int[] cnt = new int[50];
+ for (int x = lowLimit; x <= highLimit; x++) {
+ int y = 0;
+ int n = x;
+ while (n > 0) {
+ y += n % 10;
+ n /= 10;
+ }
+ cnt[y]++;
+ }
+ return cnt.Max();
+ }
+}
+```
+
diff --git a/solution/1700-1799/1742.Maximum Number of Balls in a Box/Solution.cs b/solution/1700-1799/1742.Maximum Number of Balls in a Box/Solution.cs
new file mode 100644
index 0000000000000..70de08a91ab94
--- /dev/null
+++ b/solution/1700-1799/1742.Maximum Number of Balls in a Box/Solution.cs
@@ -0,0 +1,15 @@
+public class Solution {
+ public int CountBalls(int lowLimit, int highLimit) {
+ int[] cnt = new int[50];
+ for (int x = lowLimit; x <= highLimit; x++) {
+ int y = 0;
+ int n = x;
+ while (n > 0) {
+ y += n % 10;
+ n /= 10;
+ }
+ cnt[y]++;
+ }
+ return cnt.Max();
+ }
+}
diff --git a/solution/1700-1799/1742.Maximum Number of Balls in a Box/Solution.js b/solution/1700-1799/1742.Maximum Number of Balls in a Box/Solution.js
new file mode 100644
index 0000000000000..53c0f0670b57e
--- /dev/null
+++ b/solution/1700-1799/1742.Maximum Number of Balls in a Box/Solution.js
@@ -0,0 +1,16 @@
+/**
+ * @param {number} lowLimit
+ * @param {number} highLimit
+ * @return {number}
+ */
+var countBalls = function (lowLimit, highLimit) {
+ const cnt = Array(50).fill(0);
+ for (let i = lowLimit; i <= highLimit; ++i) {
+ let y = 0;
+ for (let x = i; x; x = Math.floor(x / 10)) {
+ y += x % 10;
+ }
+ ++cnt[y];
+ }
+ return Math.max(...cnt);
+};
diff --git a/solution/1700-1799/1742.Maximum Number of Balls in a Box/Solution.rs b/solution/1700-1799/1742.Maximum Number of Balls in a Box/Solution.rs
new file mode 100644
index 0000000000000..8d0cd508c82ac
--- /dev/null
+++ b/solution/1700-1799/1742.Maximum Number of Balls in a Box/Solution.rs
@@ -0,0 +1,15 @@
+impl Solution {
+ pub fn count_balls(low_limit: i32, high_limit: i32) -> i32 {
+ let mut cnt = vec![0; 50];
+ for x in low_limit..=high_limit {
+ let mut y = 0;
+ let mut n = x;
+ while n > 0 {
+ y += n % 10;
+ n /= 10;
+ }
+ cnt[y as usize] += 1;
+ }
+ *cnt.iter().max().unwrap()
+ }
+}
diff --git a/solution/3400-3499/3451.Find Invalid IP Addresses/README.md b/solution/3400-3499/3451.Find Invalid IP Addresses/README.md
new file mode 100644
index 0000000000000..c09c41e732002
--- /dev/null
+++ b/solution/3400-3499/3451.Find Invalid IP Addresses/README.md
@@ -0,0 +1,162 @@
+---
+comments: true
+difficulty: 困难
+edit_url: https://github.com/doocs/leetcode/edit/main/solution/3400-3499/3451.Find%20Invalid%20IP%20Addresses/README.md
+tags:
+ - 数据库
+---
+
+
+
+# [3451. Find Invalid IP Addresses](https://leetcode.cn/problems/find-invalid-ip-addresses)
+
+[English Version](/solution/3400-3499/3451.Find%20Invalid%20IP%20Addresses/README_EN.md)
+
+## 题目描述
+
+
+
+Table: logs
+
+
++-------------+---------+
+| Column Name | Type |
++-------------+---------+
+| log_id | int |
+| ip | varchar |
+| status_code | int |
++-------------+---------+
+log_id is the unique key for this table.
+Each row contains server access log information including IP address and HTTP status code.
+
+
+Write a solution to find invalid IP addresses. An IPv4 address is invalid if it meets any of these conditions:
+
+
+ - Contains numbers greater than
255 in any octet
+ - Has leading zeros in any octet (like
01.02.03.04)
+ - Has less or more than
4 octets
+
+
+Return the result table ordered by invalid_count, ip in descending order respectively.
+
+The result format is in the following example.
+
+
+Example:
+
+
+
Input:
+
+
logs table:
+
+
++--------+---------------+-------------+
+| log_id | ip | status_code |
++--------+---------------+-------------+
+| 1 | 192.168.1.1 | 200 |
+| 2 | 256.1.2.3 | 404 |
+| 3 | 192.168.001.1 | 200 |
+| 4 | 192.168.1.1 | 200 |
+| 5 | 192.168.1 | 500 |
+| 6 | 256.1.2.3 | 404 |
+| 7 | 192.168.001.1 | 200 |
++--------+---------------+-------------+
+
+
+
Output:
+
+
++---------------+--------------+
+| ip | invalid_count|
++---------------+--------------+
+| 256.1.2.3 | 2 |
+| 192.168.001.1 | 2 |
+| 192.168.1 | 1 |
++---------------+--------------+
+
+
+
Explanation:
+
+
+ - 256.1.2.3 is invalid because 256 > 255
+ - 192.168.001.1 is invalid because of leading zeros
+ - 192.168.1 is invalid because it has only 3 octets
+
+
+
The output table is ordered by invalid_count, ip in descending order respectively.
+
Table: logs
+
+
++-------------+---------+
+| Column Name | Type |
++-------------+---------+
+| log_id | int |
+| ip | varchar |
+| status_code | int |
++-------------+---------+
+log_id is the unique key for this table.
+Each row contains server access log information including IP address and HTTP status code.
+
+
+Write a solution to find invalid IP addresses. An IPv4 address is invalid if it meets any of these conditions:
+
+
+ - Contains numbers greater than
255 in any octet
+ - Has leading zeros in any octet (like
01.02.03.04)
+ - Has less or more than
4 octets
+
+
+Return the result table ordered by invalid_count, ip in descending order respectively.
+
+The result format is in the following example.
+
+
+Example:
+
+
+
Input:
+
+
logs table:
+
+
++--------+---------------+-------------+
+| log_id | ip | status_code |
++--------+---------------+-------------+
+| 1 | 192.168.1.1 | 200 |
+| 2 | 256.1.2.3 | 404 |
+| 3 | 192.168.001.1 | 200 |
+| 4 | 192.168.1.1 | 200 |
+| 5 | 192.168.1 | 500 |
+| 6 | 256.1.2.3 | 404 |
+| 7 | 192.168.001.1 | 200 |
++--------+---------------+-------------+
+
+
+
Output:
+
+
++---------------+--------------+
+| ip | invalid_count|
++---------------+--------------+
+| 256.1.2.3 | 2 |
+| 192.168.001.1 | 2 |
+| 192.168.1 | 1 |
++---------------+--------------+
+
+
+
Explanation:
+
+
+ - 256.1.2.3 is invalid because 256 > 255
+ - 192.168.001.1 is invalid because of leading zeros
+ - 192.168.1 is invalid because it has only 3 octets
+
+
+
The output table is ordered by invalid_count, ip in descending order respectively.
+