# 443. String Compression | LeetCode Solution

## 443. String Compression

Given an array of characters `chars`, compress it using the following algorithm:

Begin with an empty string `s`. For each group of consecutive repeating characters in `chars`:

• If the group's length is `1`, append the character to `s`.
• Otherwise, append the character followed by the group's length.

The compressed string `s` should not be returned separately, but instead, be stored in the input character array `chars`. Note that group lengths that are `10` or longer will be split into multiple characters in `chars`.

After you are done modifying the input array, return the new length of the array.

You must write an algorithm that uses only constant extra space.

Example 1:

```Input: chars = ["a","a","b","b","c","c","c"]
Output: Return 6, and the first 6 characters of the input array should be: ["a","2","b","2","c","3"]
Explanation: The groups are "aa", "bb", and "ccc". This compresses to "a2b2c3".
```

Example 2:

```Input: chars = ["a"]
Output: Return 1, and the first character of the input array should be: ["a"]
Explanation: The only group is "a", which remains uncompressed since it's a single character.
```

Example 3:

```Input: chars = ["a","b","b","b","b","b","b","b","b","b","b","b","b"]
Output: Return 4, and the first 4 characters of the input array should be: ["a","b","1","2"].
Explanation: The groups are "a" and "bbbbbbbbbbbb". This compresses to "ab12".```

Constraints:

• `1 <= chars.length <= 2000`
• `chars[i]` is a lowercase English letter, uppercase English letter, digit, or symbol.

1. CREATE TABLE STUDENT_TABLE ( SNO INT , ROLLNO INT, ENROLL INT , STUDENT_NAME varchar(50), COURSEID INT , EMAILID VARCHAR(50) , MOBILE varchar(10));
INSERT INTO STUDENT_TABLE VALUES (1 , 20115001 , 200561, "AADI REDHU" , 101 , "aadi@email.com" , "998587654");
INSERT INTO STUDENT_TABLE VALUES (2 , 20115002 , 200461, "AAYUSH" , 104 , "ayush@email.com" , "998581654");
INSERT INTO STUDENT_TABLE VALUES (3 , 20115003 , 200581, "ABHINAV" , 109 , "abhinav@email.com" , "978587654");
INSERT INTO STUDENT_TABLE VALUES (4 , 20115004 , 200961, "ajay" , 107 , "ajay@email.com" , "998587154");
INSERT INTO STUDENT_TABLE VALUES (5 , 20115005 , 200361, "raunit" , 102 , "raunit@email.com" , "998537654");

SELECT * FROM STUDENT_TABLE;
DELIMITER &&
CREATE PROCEDURE merit()
BEGIN
select * FROM STUDENT_TABLE WHERE COURSEID > 102;
END &&
DELIMITER;
CALL merit();

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