Mixed Pattern Battle
Train the reflex of naming the right pattern before you touch the keyboard.
0 of 5 problems solved
Mixed Pattern Battle
Train the reflex of naming the right pattern before you touch the keyboard.
- •What clue in the prompt points to a specific pattern first?
- •Can I name the pattern before I even think about syntax?
- •Am I choosing the tool that matches the problem shape, not my favorite template?
Mixed Pattern Battle is where you stop asking 'How do I code this?' and start asking the better question first: 'What kind of problem is this?' By now you have several tools. The win is not memorizing them individually. The win is reaching for the right one quickly when the prompt looks random.
The best speed boost in DSA is choosing the right pattern before writing a single line.
- 1Read the prompt and extract the strongest clues: sorted array, duplicates, range sum, graph, levels, target, and so on.
- 2Match those clues to likely patterns instead of jumping straight into syntax.
- 3Say the pattern out loud before you code.
- 4Only then sketch the solution skeleton.
Treating every new problem like a brand-new invention wastes time. Most of the time, it is an old pattern in a new costume.
Battle Round: First Missing Positive
Put value k at index k-1 for all 1 <= k <= n using the array as its own hash. Then scan for the first index where value != index + 1.