-
Input: grid = [[0,0],[1,0]]
+
Input: grid = [[1,0],[0,0]]
Output: 1
diff --git a/solution/3100-3199/3198.Find Cities in Each State/README.md b/solution/3100-3199/3198.Find Cities in Each State/README.md
new file mode 100644
index 0000000000000..d340f3d27c5d0
--- /dev/null
+++ b/solution/3100-3199/3198.Find Cities in Each State/README.md
@@ -0,0 +1,128 @@
+---
+comments: true
+difficulty: 简单
+edit_url: https://github.com/doocs/leetcode/edit/main/solution/3100-3199/3198.Find%20Cities%20in%20Each%20State/README.md
+---
+
+
+
+# [3198. 查找每个州的城市 🔒](https://leetcode.cn/problems/find-cities-in-each-state)
+
+[English Version](/solution/3100-3199/3198.Find%20Cities%20in%20Each%20State/README_EN.md)
+
+## 题目描述
+
+
+
+
表：cities
+
+
++-------------+---------+
+| Column Name | Type |
++-------------+---------+
+| state | varchar |
+| city | varchar |
++-------------+---------+
+(state, city) 是这张表的主键（有不同值的列的组合）。
+这张表的每一行包含州名和其中的城市名。
+
+
+
编写一个解决方案来 查找每个州的所有城市，并将它们组合成 一个逗号分隔 的字符串。
+
+
返回结果表以 state 升序 排序。
+
+
结果格式如下所示。
+
+
+
+
示例：
+
+
+
输入：
+
+
cities 表：
+
+
++-------------+---------------+
+| state | city |
++-------------+---------------+
+| California | Los Angeles |
+| California | San Francisco |
+| California | San Diego |
+| Texas | Houston |
+| Texas | Austin |
+| Texas | Dallas |
+| New York | New York City |
+| New York | Buffalo |
+| New York | Rochester |
++-------------+---------------+
+
+
+
输出：
+
+
++-------------+---------------------------------------+
+| state | cities |
++-------------+---------------------------------------+
+| California | Los Angeles, San Diego, San Francisco |
+| New York | Buffalo, New York City, Rochester |
+| Texas | Austin, Dallas, Houston |
++-------------+---------------------------------------+
+
+
+
解释：
+
+
+ - California：所有城市 ("Los Angeles", "San Diego", "San Francisco") 以逗号分隔的字符串列出。
+ - New York：所有城市 ("Buffalo", "New York City", "Rochester") 以逗号分隔的字符串列出。
+ - Texas：所有城市 ("Austin", "Dallas", "Houston") 以逗号分隔的字符串列出。
+
+
+
注意：输出表以州名升序排序。
+
+
+
+
+## 解法
+
+
+
+### 方法一：分组聚合
+
+我们可以先按照 `state` 字段进行分组，然后对每个分组内的 `city` 字段进行排序，最后使用 `GROUP_CONCAT` 函数将排序后的城市名连接成一个逗号分隔的字符串。
+
+
+
+#### MySQL
+
+```sql
+# Write your MySQL query statement below
+SELECT
+ state,
+ GROUP_CONCAT(city ORDER BY city SEPARATOR ', ') cities
+FROM cities
+GROUP BY 1
+ORDER BY 1;
+```
+
+#### Pandas
+
+```python
+import pandas as pd
+
+
+def find_cities(cities: pd.DataFrame) -> pd.DataFrame:
+ result = (
+ cities.groupby("state")["city"]
+ .apply(lambda x: ", ".join(sorted(x)))
+ .reset_index()
+ )
+ result.columns = ["state", "cities"]
+ return result
+```
+
+
+
+
+
+
diff --git a/solution/3100-3199/3198.Find Cities in Each State/README_EN.md b/solution/3100-3199/3198.Find Cities in Each State/README_EN.md
new file mode 100644
index 0000000000000..996bb54bffad1
--- /dev/null
+++ b/solution/3100-3199/3198.Find Cities in Each State/README_EN.md
@@ -0,0 +1,127 @@
+---
+comments: true
+difficulty: Easy
+edit_url: https://github.com/doocs/leetcode/edit/main/solution/3100-3199/3198.Find%20Cities%20in%20Each%20State/README_EN.md
+---
+
+
+
+# [3198. Find Cities in Each State 🔒](https://leetcode.com/problems/find-cities-in-each-state)
+
+[中文文档](/solution/3100-3199/3198.Find%20Cities%20in%20Each%20State/README.md)
+
+## Description
+
+
+
+
Table: cities
+
+
++-------------+---------+
+| Column Name | Type |
++-------------+---------+
+| state | varchar |
+| city | varchar |
++-------------+---------+
+(state, city) is the primary key (combination of columns with unique values) for this table.
+Each row of this table contains the state name and the city name within that state.
+
+
+
Write a solution to find all the cities in each state and combine them into a single comma-separated string.
+
+
Return the result table ordered by state in ascending order.
+
+
The result format is in the following example.
+
+
+
Example:
+
+
+
Input:
+
+
cities table:
+
+
++-------------+---------------+
+| state | city |
++-------------+---------------+
+| California | Los Angeles |
+| California | San Francisco |
+| California | San Diego |
+| Texas | Houston |
+| Texas | Austin |
+| Texas | Dallas |
+| New York | New York City |
+| New York | Buffalo |
+| New York | Rochester |
++-------------+---------------+
+
+
+
Output:
+
+
++-------------+---------------------------------------+
+| state | cities |
++-------------+---------------------------------------+
+| California | Los Angeles, San Diego, San Francisco |
+| New York | Buffalo, New York City, Rochester |
+| Texas | Austin, Dallas, Houston |
++-------------+---------------------------------------+
+
+
+
Explanation:
+
+
+ - California: All cities ("Los Angeles", "San Diego", "San Francisco") are listed in a comma-separated string.
+ - New York: All cities ("Buffalo", "New York City", "Rochester") are listed in a comma-separated string.
+ - Texas: All cities ("Austin", "Dallas", "Houston") are listed in a comma-separated string.
+
+
+
Note: The output table is ordered by the state name in ascending order.
+
+
+
+
+## Solutions
+
+
+
+### Solution 1: Grouping and Aggregation
+
+We can first group by the `state` field, then sort the `city` field within each group, and finally use the `GROUP_CONCAT` function to concatenate the sorted city names into a comma-separated string.
+
+
+
+#### MySQL
+
+```sql
+# Write your MySQL query statement below
+SELECT
+ state,
+ GROUP_CONCAT(city ORDER BY city SEPARATOR ', ') cities
+FROM cities
+GROUP BY 1
+ORDER BY 1;
+```
+
+#### Pandas
+
+```python
+import pandas as pd
+
+
+def find_cities(cities: pd.DataFrame) -> pd.DataFrame:
+ result = (
+ cities.groupby("state")["city"]
+ .apply(lambda x: ", ".join(sorted(x)))
+ .reset_index()
+ )
+ result.columns = ["state", "cities"]
+ return result
+```
+
+
+
+
+
+
diff --git a/solution/3100-3199/3198.Find Cities in Each State/Solution.py b/solution/3100-3199/3198.Find Cities in Each State/Solution.py
new file mode 100644
index 0000000000000..6feb669ac2c73
--- /dev/null
+++ b/solution/3100-3199/3198.Find Cities in Each State/Solution.py
@@ -0,0 +1,11 @@
+import pandas as pd
+
+
+def find_cities(cities: pd.DataFrame) -> pd.DataFrame:
+ result = (
+ cities.groupby("state")["city"]
+ .apply(lambda x: ", ".join(sorted(x)))
+ .reset_index()
+ )
+ result.columns = ["state", "cities"]
+ return result
diff --git a/solution/3100-3199/3198.Find Cities in Each State/Solution.sql b/solution/3100-3199/3198.Find Cities in Each State/Solution.sql
new file mode 100644
index 0000000000000..1e8dbc7d8633e
--- /dev/null
+++ b/solution/3100-3199/3198.Find Cities in Each State/Solution.sql
@@ -0,0 +1,7 @@
+# Write your MySQL query statement below
+SELECT
+ state,
+ GROUP_CONCAT(city ORDER BY city SEPARATOR ', ') cities
+FROM cities
+GROUP BY 1
+ORDER BY 1;
\ No newline at end of file
diff --git a/solution/DATABASE_README.md b/solution/DATABASE_README.md
index 969dd0a0f92ec..77ef150eb991a 100644
--- a/solution/DATABASE_README.md
+++ b/solution/DATABASE_README.md
@@ -283,7 +283,8 @@
| 3166 | [计算停车费与时长](/solution/3100-3199/3166.Calculate%20Parking%20Fees%20and%20Duration/README.md) | `数据库` | 中等 | 🔒 |
| 3172 | [第二天验证](/solution/3100-3199/3172.Second%20Day%20Verification/README.md) | `数据库` | 简单 | 🔒 |
| 3182 | [查找得分最高的学生](/solution/3100-3199/3182.Find%20Top%20Scoring%20Students/README.md) | `数据库` | 中等 | 🔒 |
-| 3188 | [查找得分最高的学生 II](/solution/3100-3199/3188.Find%20Top%20Scoring%20Students%20II/README.md) | | 困难 | 🔒 |
+| 3188 | [查找得分最高的学生 II](/solution/3100-3199/3188.Find%20Top%20Scoring%20Students%20II/README.md) | `数据库` | 困难 | 🔒 |
+| 3198 | [查找每个州的城市](/solution/3100-3199/3198.Find%20Cities%20in%20Each%20State/README.md) | | 简单 | 🔒 |
## 版权
diff --git a/solution/DATABASE_README_EN.md b/solution/DATABASE_README_EN.md
index b9febbe7756e1..064fcaa4f9f92 100644
--- a/solution/DATABASE_README_EN.md
+++ b/solution/DATABASE_README_EN.md
@@ -281,7 +281,8 @@ Press
Control +
F(or
Command +
F on
| 3166 | [Calculate Parking Fees and Duration](/solution/3100-3199/3166.Calculate%20Parking%20Fees%20and%20Duration/README_EN.md) | `Database` | Medium | 🔒 |
| 3172 | [Second Day Verification](/solution/3100-3199/3172.Second%20Day%20Verification/README_EN.md) | `Database` | Easy | 🔒 |
| 3182 | [Find Top Scoring Students](/solution/3100-3199/3182.Find%20Top%20Scoring%20Students/README_EN.md) | `Database` | Medium | 🔒 |
-| 3188 | [Find Top Scoring Students II](/solution/3100-3199/3188.Find%20Top%20Scoring%20Students%20II/README_EN.md) | | Hard | 🔒 |
+| 3188 | [Find Top Scoring Students II](/solution/3100-3199/3188.Find%20Top%20Scoring%20Students%20II/README_EN.md) | `Database` | Hard | 🔒 |
+| 3198 | [Find Cities in Each State](/solution/3100-3199/3198.Find%20Cities%20in%20Each%20State/README_EN.md) | | Easy | 🔒 |
## Copyright
diff --git a/solution/README.md b/solution/README.md
index a9b1395672282..def134542b051 100644
--- a/solution/README.md
+++ b/solution/README.md
@@ -3198,16 +3198,17 @@
| 3185 | [构成整天的下标对数目 II](/solution/3100-3199/3185.Count%20Pairs%20That%20Form%20a%20Complete%20Day%20II/README.md) | `数组`,`哈希表`,`计数` | 中等 | 第 402 场周赛 |
| 3186 | [施咒的最大总伤害](/solution/3100-3199/3186.Maximum%20Total%20Damage%20With%20Spell%20Casting/README.md) | `数组`,`哈希表`,`双指针`,`二分查找`,`动态规划`,`计数`,`排序` | 中等 | 第 402 场周赛 |
| 3187 | [数组中的峰值](/solution/3100-3199/3187.Peaks%20in%20Array/README.md) | `树状数组`,`线段树`,`数组` | 困难 | 第 402 场周赛 |
-| 3188 | [查找得分最高的学生 II](/solution/3100-3199/3188.Find%20Top%20Scoring%20Students%20II/README.md) | | 困难 | 🔒 |
-| 3189 | [Minimum Moves to Get a Peaceful Board](/solution/3100-3199/3189.Minimum%20Moves%20to%20Get%20a%20Peaceful%20Board/README.md) | | 中等 | 🔒 |
-| 3190 | [使所有元素都可以被 3 整除的最少操作数](/solution/3100-3199/3190.Find%20Minimum%20Operations%20to%20Make%20All%20Elements%20Divisible%20by%20Three/README.md) | | 简单 | 第 133 场双周赛 |
-| 3191 | [使二进制数组全部等于 1 的最少操作次数 I](/solution/3100-3199/3191.Minimum%20Operations%20to%20Make%20Binary%20Array%20Elements%20Equal%20to%20One%20I/README.md) | | 中等 | 第 133 场双周赛 |
-| 3192 | [使二进制数组全部等于 1 的最少操作次数 II](/solution/3100-3199/3192.Minimum%20Operations%20to%20Make%20Binary%20Array%20Elements%20Equal%20to%20One%20II/README.md) | | 中等 | 第 133 场双周赛 |
-| 3193 | [统计逆序对的数目](/solution/3100-3199/3193.Count%20the%20Number%20of%20Inversions/README.md) | | 困难 | 第 133 场双周赛 |
-| 3194 | [最小元素和最大元素的最小平均值](/solution/3100-3199/3194.Minimum%20Average%20of%20Smallest%20and%20Largest%20Elements/README.md) | | 简单 | 第 403 场周赛 |
+| 3188 | [查找得分最高的学生 II](/solution/3100-3199/3188.Find%20Top%20Scoring%20Students%20II/README.md) | `数据库` | 困难 | 🔒 |
+| 3189 | [得到一个和平棋盘的最少步骤](/solution/3100-3199/3189.Minimum%20Moves%20to%20Get%20a%20Peaceful%20Board/README.md) | `贪心`,`数组`,`计数排序`,`排序` | 中等 | 🔒 |
+| 3190 | [使所有元素都可以被 3 整除的最少操作数](/solution/3100-3199/3190.Find%20Minimum%20Operations%20to%20Make%20All%20Elements%20Divisible%20by%20Three/README.md) | `数组`,`数学` | 简单 | 第 133 场双周赛 |
+| 3191 | [使二进制数组全部等于 1 的最少操作次数 I](/solution/3100-3199/3191.Minimum%20Operations%20to%20Make%20Binary%20Array%20Elements%20Equal%20to%20One%20I/README.md) | `位运算`,`队列`,`数组`,`前缀和`,`滑动窗口` | 中等 | 第 133 场双周赛 |
+| 3192 | [使二进制数组全部等于 1 的最少操作次数 II](/solution/3100-3199/3192.Minimum%20Operations%20to%20Make%20Binary%20Array%20Elements%20Equal%20to%20One%20II/README.md) | `贪心`,`数组`,`动态规划` | 中等 | 第 133 场双周赛 |
+| 3193 | [统计逆序对的数目](/solution/3100-3199/3193.Count%20the%20Number%20of%20Inversions/README.md) | `数组`,`动态规划` | 困难 | 第 133 场双周赛 |
+| 3194 | [最小元素和最大元素的最小平均值](/solution/3100-3199/3194.Minimum%20Average%20of%20Smallest%20and%20Largest%20Elements/README.md) | `数组`,`双指针`,`排序` | 简单 | 第 403 场周赛 |
| 3195 | [包含所有 1 的最小矩形面积 I](/solution/3100-3199/3195.Find%20the%20Minimum%20Area%20to%20Cover%20All%20Ones%20I/README.md) | | 中等 | 第 403 场周赛 |
| 3196 | [最大化子数组的总成本](/solution/3100-3199/3196.Maximize%20Total%20Cost%20of%20Alternating%20Subarrays/README.md) | | 中等 | 第 403 场周赛 |
| 3197 | [包含所有 1 的最小矩形面积 II](/solution/3100-3199/3197.Find%20the%20Minimum%20Area%20to%20Cover%20All%20Ones%20II/README.md) | | 困难 | 第 403 场周赛 |
+| 3198 | [查找每个州的城市](/solution/3100-3199/3198.Find%20Cities%20in%20Each%20State/README.md) | | 简单 | 🔒 |
## 版权
diff --git a/solution/README_EN.md b/solution/README_EN.md
index 00ccaf1eccdc6..fa8bd6e2b70ea 100644
--- a/solution/README_EN.md
+++ b/solution/README_EN.md
@@ -3196,16 +3196,17 @@ Press
Control +
F(or
Command +
F on
| 3185 | [Count Pairs That Form a Complete Day II](/solution/3100-3199/3185.Count%20Pairs%20That%20Form%20a%20Complete%20Day%20II/README_EN.md) | `Array`,`Hash Table`,`Counting` | Medium | Weekly Contest 402 |
| 3186 | [Maximum Total Damage With Spell Casting](/solution/3100-3199/3186.Maximum%20Total%20Damage%20With%20Spell%20Casting/README_EN.md) | `Array`,`Hash Table`,`Two Pointers`,`Binary Search`,`Dynamic Programming`,`Counting`,`Sorting` | Medium | Weekly Contest 402 |
| 3187 | [Peaks in Array](/solution/3100-3199/3187.Peaks%20in%20Array/README_EN.md) | `Binary Indexed Tree`,`Segment Tree`,`Array` | Hard | Weekly Contest 402 |
-| 3188 | [Find Top Scoring Students II](/solution/3100-3199/3188.Find%20Top%20Scoring%20Students%20II/README_EN.md) | | Hard | 🔒 |
-| 3189 | [Minimum Moves to Get a Peaceful Board](/solution/3100-3199/3189.Minimum%20Moves%20to%20Get%20a%20Peaceful%20Board/README_EN.md) | | Medium | 🔒 |
-| 3190 | [Find Minimum Operations to Make All Elements Divisible by Three](/solution/3100-3199/3190.Find%20Minimum%20Operations%20to%20Make%20All%20Elements%20Divisible%20by%20Three/README_EN.md) | | Easy | Biweekly Contest 133 |
-| 3191 | [Minimum Operations to Make Binary Array Elements Equal to One I](/solution/3100-3199/3191.Minimum%20Operations%20to%20Make%20Binary%20Array%20Elements%20Equal%20to%20One%20I/README_EN.md) | | Medium | Biweekly Contest 133 |
-| 3192 | [Minimum Operations to Make Binary Array Elements Equal to One II](/solution/3100-3199/3192.Minimum%20Operations%20to%20Make%20Binary%20Array%20Elements%20Equal%20to%20One%20II/README_EN.md) | | Medium | Biweekly Contest 133 |
-| 3193 | [Count the Number of Inversions](/solution/3100-3199/3193.Count%20the%20Number%20of%20Inversions/README_EN.md) | | Hard | Biweekly Contest 133 |
-| 3194 | [Minimum Average of Smallest and Largest Elements](/solution/3100-3199/3194.Minimum%20Average%20of%20Smallest%20and%20Largest%20Elements/README_EN.md) | | Easy | Weekly Contest 403 |
+| 3188 | [Find Top Scoring Students II](/solution/3100-3199/3188.Find%20Top%20Scoring%20Students%20II/README_EN.md) | `Database` | Hard | 🔒 |
+| 3189 | [Minimum Moves to Get a Peaceful Board](/solution/3100-3199/3189.Minimum%20Moves%20to%20Get%20a%20Peaceful%20Board/README_EN.md) | `Greedy`,`Array`,`Counting Sort`,`Sorting` | Medium | 🔒 |
+| 3190 | [Find Minimum Operations to Make All Elements Divisible by Three](/solution/3100-3199/3190.Find%20Minimum%20Operations%20to%20Make%20All%20Elements%20Divisible%20by%20Three/README_EN.md) | `Array`,`Math` | Easy | Biweekly Contest 133 |
+| 3191 | [Minimum Operations to Make Binary Array Elements Equal to One I](/solution/3100-3199/3191.Minimum%20Operations%20to%20Make%20Binary%20Array%20Elements%20Equal%20to%20One%20I/README_EN.md) | `Bit Manipulation`,`Queue`,`Array`,`Prefix Sum`,`Sliding Window` | Medium | Biweekly Contest 133 |
+| 3192 | [Minimum Operations to Make Binary Array Elements Equal to One II](/solution/3100-3199/3192.Minimum%20Operations%20to%20Make%20Binary%20Array%20Elements%20Equal%20to%20One%20II/README_EN.md) | `Greedy`,`Array`,`Dynamic Programming` | Medium | Biweekly Contest 133 |
+| 3193 | [Count the Number of Inversions](/solution/3100-3199/3193.Count%20the%20Number%20of%20Inversions/README_EN.md) | `Array`,`Dynamic Programming` | Hard | Biweekly Contest 133 |
+| 3194 | [Minimum Average of Smallest and Largest Elements](/solution/3100-3199/3194.Minimum%20Average%20of%20Smallest%20and%20Largest%20Elements/README_EN.md) | `Array`,`Two Pointers`,`Sorting` | Easy | Weekly Contest 403 |
| 3195 | [Find the Minimum Area to Cover All Ones I](/solution/3100-3199/3195.Find%20the%20Minimum%20Area%20to%20Cover%20All%20Ones%20I/README_EN.md) | | Medium | Weekly Contest 403 |
| 3196 | [Maximize Total Cost of Alternating Subarrays](/solution/3100-3199/3196.Maximize%20Total%20Cost%20of%20Alternating%20Subarrays/README_EN.md) | | Medium | Weekly Contest 403 |
| 3197 | [Find the Minimum Area to Cover All Ones II](/solution/3100-3199/3197.Find%20the%20Minimum%20Area%20to%20Cover%20All%20Ones%20II/README_EN.md) | | Hard | Weekly Contest 403 |
+| 3198 | [Find Cities in Each State](/solution/3100-3199/3198.Find%20Cities%20in%20Each%20State/README_EN.md) | | Easy | 🔒 |
## Copyright
@@ -37,19 +37,19 @@ tags:
输出：3
-
-
