string compression problem lecture 32 leetcode 443

certainly! the string compression problem is a common coding interview question that tests your understanding of string manipulation and array handling. the problem is defined as follows:

problem statement
you are given a character array `chars` that consists of an uncompressed string. you need to compress it using the following algorithm:

1. begin with an empty string `result`.
2. for each group of consecutive identical characters in `chars`, append the character followed by the number of occurrences (if greater than 1) to `result`.
3. modify the original array `chars` in place to store the compressed version of the string.
4. the function should return the new length of the compressed string.

example
for example, given the input:
```plaintext
chars = ["a", "a", "b", "b", "c", "c", "c"]
```
the output should be:
```plaintext
6
```
and the first `6` elements of `chars` should be modified to:
```plaintext
["a", "2", "b", "2", "c", "3"]
```

steps to solve the problem
1. **initialization**: use a pointer to keep track of the current position in the `chars` array.
2. **iteration**: iterate through the array, counting consecutive characters.
3. **compression**: when a different character is encountered (or the end of the array is reached), write the character and its count (if greater than 1) back to the array.
4. **return**: finally, return the length of the compressed array.

implementation
here's a python implementation of the above logic:

```python
def compress(chars):
write_index = 0 pointer for writing the compressed data
read_index = 0 pointer for reading the original data

while read_index len(chars):
current_char = chars[read_index]
count = 0

count occurrences of the current character
while read_index len(chars) and chars[read_index] == current_char:
read_index += 1
count += 1

write the character to the compressed array
chars[write_index] = c ...

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String compression
LeetCode 443
algorithm
data structures
run-length encoding
compression techniques
character encoding
string manipulation
space optimization
array modification
in-place algorithm
time complexity
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