[LeetCode] 384. Shuffle an Array

轉自LeetCode

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();

<Solution>

這題不難

保留一個原始 input 給 reset 用

然後用 std::next_permutaion 來實做 shuffle 即可

code 如下
c++

	class Solution {
	public:
	Solution(vector<int> nums)
	: original(nums)
	, res(nums) {
	}
	/** Resets the array to its original configuration and return it. */
	vector<int> reset() {
	return original;
	}
	/** Returns a random shuffling of the array. */
	vector<int> shuffle() {
	next_permutation(res.begin(), res.end());
	return res;
	}
	private:
	vector<int> original;
	vector<int> res;
	};

view raw shuffle.cpp hosted with ❤ by GitHub

kotlin

	class Solution(nums: IntArray) {
	private lateinit var original: IntArray
	private var values = mutableListOf<Int>()
	init {
	original = nums
	values.addAll(nums.toList())
	}
	fun reset(): IntArray {
	return original
	}
	fun shuffle(): IntArray {
	values.shuffle()
	return values.toIntArray()
	}
	}
	/**
	* Your Solution object will be instantiated and called as such:
	* var obj = Solution(nums)
	* var param_1 = obj.reset()
	* var param_2 = obj.shuffle()
	*/

view raw shuffle_an_array.kt hosted with ❤ by GitHub