g0401_0500.s0443_string_compression.Solution

public class Solution extends Object

443 - String Compression.Medium Given an array of characters <code>chars</code>, compress it using the following algorithm: Begin with an empty string <code>s</code>. For each group of consecutive repeating characters in <code>chars</code>: <ul> <li>If the group’s length is <code>1</code>, append the character to <code>s</code>.</li> <li>Otherwise, append the character followed by the group’s length.</li> </ul> The compressed string <code>s</code> should not be returned separately , but instead, be stored **in the input character array <code>chars</code> **. Note that group lengths that are <code>10</code> or longer will be split into multiple characters in <code>chars</code>. 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”. Example 4: Input: chars = [“a”,“a”,“a”,“b”,“b”,“a”,“a”] Output: Return 6, and the first 6 characters of the input array should be: [“a”,“3”,“b”,“2”,“a”,“2”]. Explanation: The groups are “aaa”, “bb”, and “aa”. This compresses to “a3b2a2”. Note that each group is independent even if two groups have the same character. Constraints: <ul> <li><code>1 <= chars.length <= 2000</code></li> <li><code>chars[i]</code> is a lowercase English letter, uppercase English letter, digit, or symbol.</li> </ul>

Constructor Summary

Constructors

Constructor

Description

Solution()
Method Summary

Modifier and Type

Method

Description

int

compress(char[] chars)

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details
- Solution
  
  public Solution()
Method Details
- compress
  
  public int compress(char[] chars)

Class Solution

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Method Summary

Methods inherited from class java.lang.Object

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Solution

Method Details

compress