Try all ways to pick characters alternately from s1 and s2 to form s3.
At each position in s3, you choose from s1 or s2. With lengths and , there are ways.
Checking each is exponential. Can you reuse partial solutions?
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$ curl repovive.com/roadmaps/pattern-22/dynamic-programming-2d/interleaving-string-why-naive-fails
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