CODING EXERCISES
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Choose a language and build confidence with focused exercises, helpful tests, and explanations that teach the underlying pattern.
373839
SQLbeginner
Page the two most recent orders
The clerk dashboard shows a short recent-orders strip. Return order_id, customer_id, and placed_on for the two newest orders. Break ties with the larger order_id first so the page is stable.
Cintermediate
Copy a string with a capacity contract
Write copy_string that copies source into destination when capacity is non-zero, always terminates the destination, and reports failure if the source will not fit.
Cintermediate
Deduplicate a sorted integer array
Remove duplicates in-place from an ascending integer array and return the number of unique values. The retained prefix must preserve ascending order.