Problem Statement
Application lab in Arrays and Dynamic Lists
Mission
Rotate a list left by k positions.
Learning outcome: Apply modular indexing to rotate a list
Correctness contract
Invariant: Elements occupy indexes 0 through size - 1, and size never exceeds capacity.
Required technique: Normalize k and place each original value at its modular destination without calling a library rotation routine.
Complexity target: time O(n); space O(n).
Input and output
Input: n, then n integers, then a non-negative rotation count k. Whitespace may be spaces or line breaks.
Output: Print the requested sequence on one line with single spaces and no trailing space. Return it as a String; Main.java prints it without adding other text.
Assumptions:
- n is positive.
- The rotation count is non-negative.
Before you code
- Restate the input and output contract, then predict the visible example without running code.
- Implement the core state transition: Normalize k and place each original value at its modular destination without calling a library rotation routine.
- Trace the smallest boundary case, verify exact formatting, and justify the authored time and auxiliary-space bounds.
Implement Practice.solve(Scanner sc). Keep every provided filename and public class name unchanged.
Sample input
5 1 2 3 4 5 2Sample output
3 4 5 1 2Why the sample works: Visible walkthrough for the ordinary non-trivial path. After reducing k modulo n, output position i reads the original value at (i + k) modulo n. Input `5 1 2 3 4 5 2` therefore produces `3 4 5 1 2`.
Progressive hints
Try the trace and first milestone before opening a hint. Open them in order.
Open hint 1Hint 1 β Contract: identify what each parsed variable represents and write the invariant beside the loop or recursive method.
Open hint 2Hint 2 β Next step: Trace the smallest non-trivial input and write the structure state after the operation before coding the loop.
Open hint 3Hint 3 β Verification: compare the structure state before and after one operation, then test the smallest valid input and a duplicate or unreachable case when allowed.