Given an integer array nums
, design an algorithm to randomly shuffle the array. All permutations of the array should be equally likely as a result of the shuffling.
Implement the Solution
class:
-
Solution(int[] nums)
Initializes the object with the integer arraynums
. -
int[] reset()
Resets the array to its original configuration and returns it. -
int[] shuffle()
Returns a random shuffling of the array.
Example 1:
Input
["Solution", "shuffle", "reset", "shuffle"]
[[[1, 2, 3]], [], [], []]
Output
[null, [3, 1, 2], [1, 2, 3], [1, 3, 2]]
Explanation
Solution solution = new Solution([1, 2, 3]);
solution.shuffle(); // Shuffle the array [1,2,3] and return its result.
// Any permutation of [1,2,3] must be equally likely to be returned.
// Example: return [3, 1, 2]
solution.reset(); // Resets the array back to its original configuration [1,2,3]. Return [1, 2, 3]
solution.shuffle(); // Returns the random shuffling of array [1,2,3]. Example: return [1, 3, 2]
Constraints:
-
1 <= nums.length <= 50
-
-106 <= nums[i] <= 106
- All the elements of
nums
are unique. - At most
104
calls in total will be made toreset
andshuffle
.
SOLUTION:
import random
class Solution:
def __init__(self, nums: List[int]):
self.nums = nums
def reset(self) -> List[int]:
return self.nums
def shuffle(self) -> List[int]:
return sorted(self.nums, key = lambda x: random.random())
# Your Solution object will be instantiated and called as such:
# obj = Solution(nums)
# param_1 = obj.reset()
# param_2 = obj.shuffle()
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