# Problem Definition

## Description

Given a string, find the length of the longest substring without repeating characters.

```python
class Solution:
  def lengthOfLongestSubstring(self, s):
    # Fill this in.

print Solution().lengthOfLongestSubstring('abrkaabcdefghijjxxx')
# 10
```

## Discussion

### Time Complexity

### Space Complexity

## Notes

## References
