Sliding Window (Max window)

Use when you want the maximum length window that satisfies a constraint, where:

• You can grow by adding s[rhs]
• If constraint breaks, you can fix it by shrinking from the left

→ “longest / maximum length”

→ “at most k …”

→ “no more than …”

→ “contains at most / at least”

→ “make window valid again by moving left”