Question Definition
Shuffle a set of numbers without duplicates. Example:
// Init an array with set 1, 2, and 3.
int[] nums = {1,2,3};
Solution solution = new Solution(nums);
// Shuffle the array [1,2,3] and return its result. Any permutation of [1,2,3] must equally likely to be returned.
solution.shuffle();
// Resets the array back to its original configuration [1,2,3].
solution.reset();
// Returns the random shuffling of array [1,2,3].
solution.shuffle();
Java Solution
class Solution {
private int[] nums;
private Random random;
public Solution(int[] nums) {
this.nums = nums;
random = new Random();
}
/** Resets the array to its original configuration and return it. */
public int[] reset() {
return nums;
}
/** Returns a random shuffling of the array. */
public int[] shuffle() {
List<Integer> list = new LinkedList<>();
for(int num : nums)
list.add(num);
int[] shuffers = new int[nums.length];
int i = 0;
while(i < nums.length) {
int randomIndex = random.nextInt(list.size());
shuffers[i] = list.get(randomIndex);
list.remove(randomIndex);
i++;
}
return shuffers;
}
}
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