Remove Duplicates from Array

The great detective Sherlock Codelmes stands before the chalkboard in his study at 221B Algorithm Street. A Bit Bender mystery has arrived on his desk: the case of "Remove Duplicates from Array". The room is thick with pipe smoke and the smell of old books. Dr. Watson waits with pen in hand, ready to record the deduction. Sherlock paces, his mind racing through patterns and possibilities. The criminal in this case is inefficiency, and the evidence lies scattered across the input data. Only a flawless program can bring the culprit to justice. The great detective Sherlock Codelmes stands before the chalkboard in his study at 221B Algorithm Street. A Bit Bender mystery has arrived on his desk: the case of "Remove Duplicates from Array". The room is thick with pipe smoke and the smell of old books. Dr. Watson waits with pen in hand, ready to record the deduction. Sherlock paces, his mind racing through patterns and possibilities. The criminal in this case is inefficiency, and the evidence lies scattered across the input data. Only a flawless program can bring the culprit to justice. Read an integer N followed by N space-separated integers on the next line. Print the array with duplicates removed (preserving first-occurrence order, space-separated). Sherlock's notebook contains the following deductions about the constraints: 1 <= N <= 10^5, -10^9 <= elements <= 10^9 For reference, Inspector Lestrade has provided these case files: Input: 9 1 1 2 2 3 3 4 4 5 Output: 1 2 3 4 5 The clock on the mantelpiece strikes midnight. Sherlock stops pacing and turns to you. "The game is afoot," he says. "Write the solution, and the truth shall be revealed." There is no room for error in the court of the Algorithmic Crown. Sherlock's notebook contains the following deductions about the constraints: 1 <= N <= 10^5, -10^9 <= elements <= 10^9 For reference, Inspector Lestrade has provided these case files: Input: 9 1 1 2 2 3 3 4 4 5 Output: 1 2 3 4 5 The clock on the mantelpiece strikes midnight. Sherlock stops pacing and turns to you. "The game is afoot," he says. "Write the solution, and the truth shall be revealed." There is no room for error in the court of the Algorithmic Crown. The path to mastering Remove Duplicates from Array is not one that can be walked in a single step. It demands patience, precision, and a deep respect for the boundaries that shape the problem. Many adventurers before you have attempted this trial and failed, their code crashing against the very constraints that the elders inscribed. But you have the tools. You have the training. You have reached the Bit Bender tier, and that alone means the council believes in your potential. Look once more at the examples above. Trace the logic with your finger if you must. Consider the time and memory limits carefully, for they are not suggestions but strict laws of the arena. When you are ready, commit your solution. Let the compiler run. Let the test cases judge your work. If your code is true, the gates will open and you will move closer to the ultimate rank. If not, study the failure, sharpen your algorithm, and try again. For in the halls of CodeTikki, the only thing more important than success is the wisdom gained from the attempt. Remember that the Bit Bender challenge is designed to test not just knowledge, but character. Every edge case is a lesson. Every time limit is a teacher. Every hidden test is a guardian at the gate. Do not rush. Let your code breathe. Let it be as clean as a mountain stream. When the final test passes, you will know that you have earned the title. Until then, code with courage, test with care, and never stop learning.